What are some math terms?

Answer 1

A

• Abacus in Various Number Systems
• Abelian group
• Abscissa
• Absolute Geometry
• Absolute value
• Absolute value of a complex number
• Absorbtion identity
• Abundant Number
• Acute angle
• Acute triangle
• Adams' Circle
• Adams' Method of Apportionment
• Addition
• Addition Formula for Sine
• Additive Inverse
• Additivity
• Adjacency
• Affine-regular Polygon
• Affine Geometry
• Affine Space
• Affine Transformation
• Affirmative Action Problem
• Alabama Paradox
• Alexander the great
• Algebraic numbers
• Algorithm
• Aliquot part
• All Triangles Are Isosceles
• Alternate Angle
• Alternating group
• Altitude
• An Airline Problem
• Anallagmatic
• Analog gadgets
• Angle
• Angle Bisectors
• Angle of incidence
• Angle of reflection
• Angle preservation property
• Angle Trisection
• Angular distance
• Annulus
• An Old Japanese Theorem
• Anticenter of a Quadrilateral
• Antichain
• Antichain in lexicographic order
• Anticommutativity
  • Anticommutative quasigroup
• Anticomplementary Triangle
  • Anticomplementary Triangle
• Antiequilic Quadrilateral
• Antihomologous
• Antiparallel
  • Antiparallel
• Antipedal triangle
• Antisymmetry
• Apollonian Gasket
• Apollonian Circles
• Apollonian Circles Theorem
  • Apollonian Circles Theorem
• Apollonian Family of Circles
• Apollonius Problem
• Apollonius' Theorem
• Apportionment Problem
• Arbelos
• Arc (in circle)
• Archimedes' Law of the Lever
• Archimedes of Syracuse
• Archimedes Triangle
• Archimedes' Lemma
• Archimedes' Method
• Archimedes' spiral
• Archimedes' Squaring of Parabola
• Archimedes' Twin Circles
• Area of a Parallelogram
• Area of a Ring
• Areal Coordinates
• Argand Diagram
• Argument of a Complex Number
• Arithmetic mean
  • Arithmetic-Geometric Mean Inequality
• Arithmetic Operations in Various Bases
• Arithmetic Paradoxes
• Arithmetic Series
• Articulation (node) of a graph
• ASA
• Assimilation Illusion
• Associativity
  • Associativity
• Associates
• Astroid
  • Astroid
• Asymmetric Propeller
  • Napoleon's Propeller
• Asymmetry
• Attractive Point
• Automaton
• Automorphism
• Axiom of Choice
• Axiom schema
• Axiomatic Completeness
• Axis of Homothety
• Axis of Symmetry of a Conic

B

• Bachet's Magic Trick
• A Baffling Prediction
• Balinski and Young's Impossibility Theorem
• Banach-Tarski Decomposition
• Bankoff's Conundrum
• Banzhaf Index
• Barbier's Theorem
  • Barbier, The Theorem of
• Barcode Encoding
• Barycenter, barycentric coordinates
  • 3 Jugs Problem
  • 3 Glasses Problem in Barycentric Coordinates
  • Barycentric coordinates and Geometric Probability
• Base Converter
  • Algorithms for Base Conversion
  • Conversion of Fractions in Various Bases
• Basic Rigid Motions of the Plane
• Basil Rennie's Lemma
• Bayes' Theorem
• Bear cubs problem
• Beatty Sequences
• Beecroft's Theorem
• Benford's Law
• Benham's Top
• Bernoulli Trials
• Bernstein theorem
• Bertrand's Paradox
• Bevan's Point and Theorem
• Bézout's Identity
• Bézout's Lemma
• Bicentric Quadrilateral
• Bicolor Towers of Hanoi
• Bijection
• Bilateral Diagram
• Bimedians (in a tetrahedron)
• Binary Encoding with the Stern-Brocot tree
• Binary Euclid's Algorithm
• Binary Relation
• Binary System
• Binet's Formula
• Binomial Coefficient
• Binomial Distribution
• Binomial Theorem
• Bipartite graph
• The Birthday Problem
• Bisectal Circle
• Bisecting arcs
• Bisecting a shape
• Bitwise shift
• Bitwise boolean operations
• Blithe 12 puzzle
• Blivet
• Block Design
• Bogus Nim
  • Bogus Nim
• Bolzano Theorem
  • Bolzano Theorem, proof
• Bookland
• Bottema's theorem
• Bound
• Bound Variable
• Boundary point
• Bounded Distance
• Brahmagupta's Theorem
• Brahmagupta's formula
• Braids Theory
• Braikenridge-Maclaurin Theorem
• Breaking Chocolate Bars
• Brianchon's theorem
• Brick Wall Illusion
• Bride's Chair
• Brocard angle
• Brocard circle
• Brocard diameter
• Brocard points
• Broken Chord Theorem
• Brouwer's Fixed Point Theorem
• Buffon�s Needle Problem
  • Math Surprises
• Bulging lines illusion
• Butterfly Theorem
  • A Better Butterfly Theorem
  • Two Butterflies Theorem
  • The Lepidoptera of the Circles
• Byzantine Basketball

C

• Cabart's Collinearity
• Cake cutting
• Calendar Magic
• Calisson
• Candy's Theorem
• Canonical Equation of Conics
• Canter
• Cantor Function
• Cantor set
  • Cantor set of positive measure
  • C0 - C0 = [-1, 1]
• Cantor's lines
• Cantor's point
• Cantor's theorem
• Cantor-Bernstein-Schroeder theorem
• Cardinal
  • Cardinal Numbers
• Cardioid
  • Hearty Munching on Cardioids
• Carnot's Theorem
• Carnot's Theorem
• Carnot's Theorem (Generalization of Wallace's Theorem on simsons)
• Carpets Theorem
• Cartesian coordinates
  • Cartesian coordinate system
• Cassini's identity
• Cauchy's inequality
• Cauchy's limit
• Cauchy sequence
• Cavalieri's Principle
• Cayley's Lines
• Cayley Table
• Cayley's Theorem
• Ceiling Function
• Cellular Automaton
• Center Circles
• Center of Inversion
• Centipede
• Central Angle
• Central Similarity
• Central Limit Theorem
• Centroid
  • Centroid, a Characteristic Property Of
• Circle of Similitude (of three directly similar figures)
• Circle of Similitude (of two circles)
• Ceva's Theorem
  • Ceva's Theorem and Fibonacci Bamboozlement
  • The Menelaus theorem
  • Trigonometric Form of Ceva's Theorem
  • Ceva is equivalent to Menelaus I
  • Ceva is equivalent to Menelaus II
• Cevian
• Cevian Nest
• Cevian Triangle
  • Cevian Triangle
• Changing Colors
• Chaos
• Characteristic Constants of the n-Line
• Characteristic function
• Chasles' Theorem
• Chebyshev polynomials
• Checker - jumping
• Chevalier de M�r�'s Problem
• Chinese Remainder Theorem
• Chord (in circle)
• Chronology of updates
• Chvatal's Art Gallery Theorem
• Circle
• Circle of Apollonius
• Circle of Concern
• Circle of Influence
• Circle-Stacking Theorem
• Circuit, same as cycle
• Circulant Matrix
  • Circulant Matrix: example
• Circular Coordinates
• Circular Poggendorff Illusion
• Circumference
• Circum-orthic Triangle
• Circumcenter
  • Existence of 1
• Circumcevian Triangle
• Circumcircle
• Circumpedal Triangle
• Circumradius
• Circumscriptible Polygon
• City-block distance
• Classification of Triangles
• Cleavance center
• Cleaver
• Clifford's Chain
• Clifford's Lemma
• Clinant
• Closed interval
• Closed set
• Closed walk
• Closure
• Coalition
• Coaxal circles
• Coaxal Circles Theorem
• Coincidence
• Collatz Conjecture
• Collinear points
• Collage Theorem
• Column vector
• Combination
• Combinatorial Proofs
• Common Fraction
• Common Notions of Euclid
• Commutative group
• Commutativity
• Compact sets
• Compactification
• Comparing complex numbers.
• Complementary angles
• Complementary event
• Complementary sequences
• Complete graph
  • Complete graph
• Complete order
• Complete Quadrangle
• Complete Quadrilateral
  • Complete Quadrilateral, the Theorem of
  • Diagonals of the complete quadrilateral
• Completeness
• Completion of a Space
• Completing the Square and Quadratic Formula
• Complex numbers
• Complex product of Complex Numbers
• Complex Projective Line
• Composite number
• Composition
• Compound Interest
• Concatenation
• Concentric circles
• Concentric polygons
• Concurrent lines
• Concyclic Points
• Conditional Probability
• Cone
• Conformal
• Congruent sets
• Congruence Modulo a Number
• Conic Sections
• Conjugate complex numbers
• Conjugate coordinates
• Conjugate Diameters in Ellipse
• Conjugate families of circles
• Conjugate points
• Conjunction
• Connected component of a graph
• Connected graph
• Connected set
• Consecutive Isosceles Decomposition
• Consistency
• Constant Chord
• Constant Random Variable
• Constant width, shapes of
• Constructible Numbers
• Construction problem
• Construction with the Compass Only
  • Rusty Compass Construction of Equilateral Triangle
• Contact Triangle
• Content
• Continuity
• Continued fraction
  • Continued Fractions on the Stern-Brocot Tree
• Continuous Line Illusion
• Continuum
• Continuum Hypothesis
• Contraction Mapping Theorem
• Convergent
• Convergent Sequence
• Convergent Series
• Converse theorem
• Convex hull
• Convex shape
• Convolution
  • Convolution
• Conway's Circle
• Coolidge theorem
• Coordinate
• Copernicus' Theorem
  • Proof of Copernicus' Theorem
• Coprime
• Cosine Rule
  • Another derivation
  • In a vector space
• Countable sets
• Counting: The Beginning of Mathematics
  • Let Them Count
• Counting numbers
• Covering A Chessboard With Domino
• Critical Player
• Cross product
• Crosscap
• Crossing Diagonal Method
• Crossing Number of a Graph
• Crossover
• Cross-Ratio
• Crossed-Lines Construction of Shapes of Constant Width
• Curve
• CTK Exchange, the
• Curry's Paradox
• Curvilinear triangle
• Cutting pipes
• Cycle (a permutation)
• Cycle (on a graph), same as circuit
• Cyclic quadrilaterals
  • Brahmagupta's Theorem
  • Four Concurrent Lines in a Cyclic Quadrilateral
  • Incenters in Cyclic Quadrilateral
  • Remarkable Line in Cyclic Quadrilateral
• Cycloids
• Cyclotomic Equation
• Cylinder

D

• Dart
• Data Structure
• Date Game
• Day's Sine Illusion
• de Bruijn cycle
• Decimal numeral
• Decomposition by Dissection
• Defect of a Langford Sequence
• Deficient Number
• Degree of a vertex
• Delboeuf Illusion
• Delian Problem
  • Delian Problem Solved
• Deliberate Ambiguities
• Deltahedron
• Deltoid
  • Steiner's Curve
• de Moivre's formula
  • de Moivre's formula
• De Moivre numbers
• de Morgan's Formulas
• Demagoguery
• Denuminator
• Dependent Events
• Dense set
• Density function
• Density (of a binary relation)
• Derangement
• Desargues' Theorem
• Descartes' formula
• Descartes' Rule of Signs
• Devil�s pitchfork
• Diagonal Count
• Diagonal matrix
• Diagonal process
• Diagonal Triangulation
• Diagonals of the complete quadrilateral
• Diameter of a circle
• Diameter of a triangulation
• Diameter of a convex shape
• Dihedral Symmetry
• Difference of two sets
• Digital Root
• Digits, fun with
• Digraph
• Dilation
• Dimensional Analysis
• Direct product
• Direct sum
• Directed Angle
• Directly Congruent Figures
• Directly Equidecomposable
• Directrix
  • Directrix of an Ellipse
• Disappearing Lines (puzzle)
• Disconnected graph
• Discovery of Duane DeTemple
• Discriminant of Quadratic Expression
  • Discriminant of Quadratic Equation
    • Disjoint Events
    • Disjunction
    • Disjunctive Rule
    • Disjunctive sum of games
    • Distance
    • Distance Between Strings
    • Distance Formula
    • Distance From a Point to a Straight Line
    • Distance on the sphere
    • Distance to the Horizon
    • Distorted Lines Illusion
    • Distributive Laws
    • Divergent Series
    • Divide a segment into n equal parts
    • Divisibility by 3
    • Divisibility by 7
    • Divisibility by 9
    • Divisibility by 11
    • Divisibility by 81
    • Divisibility Criteria
    • Divisor of zero
    • d'Ocagne's identity
    • Dodecagon
    • Dot Patterns and Sierpinski Gasket
    • Do you know that...
    • Dot product
    • Double Factorial
    • Double Generation Theorem
    • Double negative
    • Double angle formula for sine
    • Doubling the Cube
    • Douglas' Theorem
    • Drawing circles and ellipses
    • Droodles
    • Droz-Farny Circles
    • Droz-Farny Line Theorem
    • Dual to Pappus' Theorem
    • Duality
    • Duality Principle
    • Ducci Sequence
      • Ducci Sequence
    • Duplication of the Cube
    • Dumb Parrot
    • Dynamic Construction of Ellipse and Other Curves

E

• 8-connectedness
• EAN-13 encoding
• Ear
• Eccentricity
• Edge
• Egyptian Multiplication
• Egyptian Triangle
  • Egyptian Triangle By Paper Folding
• Eigenvalue
• Eigenvector
  • Eigenvectors by Inspection
• Eliminand
• Empty set
• Exterior Angles formed by a secant and parallel lines
• Epicycloids
• Eppstein's points
• Equation
• Equation of a Straight Line Through Two Points
• Equation of a Straight Line with Two Intercepts
• Equal Incircles Theorem
• Equality
• Equiangular polygon
  • A Property of Equiangular Polygons
• Equichordal points: Just Do It
• Equidecomposable shapes
• Equilateral polygon
• Equilateral triangle
• Equilic Quadrilateral
• Equivalence Relations
• The Erdös-Mordell Inequality
• Euclid's Algorithm
  • Almost Integers, Euclid's Algorithm
  • Extension of Euclid's Algorithm
• Euclid's Game
• Euclid's proof of the Pythagoras' Theorem
• Euclidean distance
• Euler Line
• Euler-Nagel Line
• Euler's Characteristic
• Euler's Formula
  • Euler's Formula
• Euler's FormulaEuler's Formula and Poncelet Porism
• Euler's Function and Congruence Theorem
• Euler-Mascheroni Constant
• Euler points
• Euler's Theorem
• Euler's Points
• Euler's Triangle
• Euler walk
• Even permutation
• Even vertex
• Evolution of Algebraic Symbolism
• Excenter
• Excentral triangle
• Excircle
• Existential Import
• Existential Quantifier
• Exscriptible Quadrilateral
• Extended Argument of a Complex Number
• Extension Fields
• Extension of Euclid's Algorithm
• Exterior Angle Theorem - an appreciation
• External Bisector
  • External Angle Bisector
• External product
• External Symmedian
• External Tangent to Two Circles
• "Extra-geometric" proofs of the Pythagorean Theorem
• Extreme
• Extreme points of convex figures
• Extreme Value Theorem
• Eyeball Theorem
• Eye Opener Series

F

• 4-connectedness
• 4 Knights
• 4 travellers problem
• 4x4 coloring problem
• Factorial
• Factorials and division
• Factoring polynomials
• Fagnano's problem
  • Fagnano's Problem, Third Solution
  • Fagnano's Problem in Reverse
  • L. Fejer's Solution
• Fair Division
  • Method fo Lone Divider
  • Method of Markers
  • Method of Sealed Bids
• Fallacy
• Farey Series
• Feasible vectors
• Fechner Colors
• Fermat's Little Theorem
• Fermat Numbers
• Fermat Point and Generalizations
  • Fermat-Torricelli Point
  • Fermat's Point
• Feuerbach's Point
• Feuerbach's Theorem
• Fibonacci sequence
  • Ceva's Theorem and Fibonacci Bamboozlement
  • Fibonacci Nim
  • Fibonacci Numbers
• Field
• Fifteen, the puzzle of
• Fifth Postulate
• Finite Cover Property
• Finite Intersection Property
  • Infinity in Compactification
• Finsler-Hadwiger theorem
• First Napoleon Point
• First Theorem of Apollonius
• Fish Soup Game
• Five Incircles Theorem
• Fixed point
  • About a Line and a Triangle
• Flank (triangle)
• Flipping pancakes
• Floor
• Focal Chord
• Focal Distance
• Focal Parameter
• Focal Radius
• Focus of a Conic
  • Foci of an Ellipse
• Folding
• Ford's touching circles
• Formal Framework
• Four 3s
• Four 4s
• Four 5s
• Four Geometric Problems of Antiquity
• Fourth Proportional
• Fractal
• Fraction Game
• Fractional part
• Free group
• Free Variable
• Friendly Kiepert's Perspectors
• Friendship
• Friendship Theorem
• Frieze Patterns
• Frogs and Toads
• Frogs and Toads in 2 dimensions
• Fulcrum
• Full angle
• Function
• Function spaces
• Functional equation
• Fundamental Theorem of 3-Bar Motion
• Fundamental Theorem of Algebra
• Fundamental Theorem of Arithmetic
  • Almost Integers, Fundamental Theorem of Arithmetic
• Fundamental Theorem of Directly Similar Figures
• Funny Arithmetic
• Fuss' Theorem

G

• Galois Extensions
• Game of Hex
• Game Theory
• Gauss-Bodenmiller theorem
• Gaussian coordinates
• Gaussian Integers
• Gelfond's theorem, Gelgond-Schneider theorem
• General Equation of a Straight Line
• General position, lines in
• Generalization in Mathematics
• Generating Function
• Genetic Algorithms
• Geoboard, Toying with the
• Geometric Constructions
• Geometric mean
  • Arithmetic-Geometric Mean Inequality
• Geometric series
  • Sum of the geometric series
• Gerbino's Illusion
• Gergonne and Van Obel Theorems
• Gergonne Line
• Gergonne Point
• Gergonne Triangle
• Gergonne's Magic Trick
• Gibbs, Josiah Willard
• Gion Shrine Problem
• Girth of a Graph
• GLaD Construction
• Glide Reflection
• Glider
• Gnomon
• Gödel's Incompleteness Theorem
• Golden rectangle
• Golden section
  • Golden Ratio in Geometry
• Golden triangle
• Googol
• Gordius, King of Phrygia
• Gradient
• Graph
• Graph Theory
• Gray codes
• Greatest Common Divisor (gcd)
• Grebe's theorem
• Greedy algorithm
• Griffiths' theorem
• Group
• Groupoid
• Growth
• Grundy number
• Grundy's Game
• Guest book

H

• Hadwiger-Finsler Inequality
• Half-axis
• Half-turn
• Hamilton Cycle
• Hamilton Path
• Hamilton's Method of Apportionment
• Hamilton's theorem
• Hamming Distance
• Handshake Lemma
• Hanoi, Tower of
• Happy 8 puzzle
• Harmonic bundle
• Harmonic conjugates
• Harmonic Mean
  • Harmonic mean
• Harmonic Ratio
• Harmonic Series
• Harmonic Triangle
• Hart Circle
• Hart's Inversor
• Hart's Theorem
• Haruki's Lemma
• Haruki's Theorem
• Hausdorff Distance
• Heaviside Step Function
• Height in a triangle, formula for
• Hering Illusion
• Heptadecagon
• Heptagon
• Heredity
• Hering Illusion
• Hermann Grid Illusion
• Heron's Formula
  • Derivation
• Heron's Problem
• Hex Can't End in a Draw
• Hex numbers
• Hilbert's Plane Filling Curve
• Hjelmslev Theorem
• Hofstadter Triangles and Points
• Hole
• Homogeneous Coordinates
• Homogeneous Functions
• Homologous
• Homothety
  • Homothety
• Hooked Langford Sequence
• Hooper's Paradox
• Hopf Fibration
• Horner's Method
• Hour glass timing
• How to define a permutation?
• Human calculators
• Hummer's Mind Reader
• Huntington-Hill's Method of Apportionment
• Huzita's axioms of paper folding
• Hyperbinary expansion
• Hypercube
• Hyperintegers and Hyperreal Numbers
• Hypocycloids

I

• Ian McGee's Observation
• Ideal elements
• Ideal subrings
• Idempotent law
• Identical Twins Puzzle
• Identical Transformation
• Identity
• Identity matrix
• iff
• Illusory contour
• Imaginary numbers
• Imaginary Part of a Complex Number
• Impartial gameA second look
• Implication
• Implicit Equation of a Straight Line
• Impossible Fork
• Impossible page
• Improper Isometry
• Incidence matrix
• Incident points and lines
• Incenter
• Incenters in Cyclic Quadrilateral
• Incircle
• Inclusion-Exclusion Principle
  • Marriage Theorem
• Incompatible Events
• Indegree
• Independent Events
• Index
• Index Lemma, the
• InductionMathematical Induction: examples
• Infinite Discent for x4 + y4 = z4
• Infinite Products
  • Convergent
  • Divergent
  • Convergent to 0
  • Divergent to 0
• Infinite Sums
• Infinitesimal
• Infinitude of Primes
• Infinity
  • Infinity and Probability
  • What Is Infinity?
• Inflectin point
• Injective function
• Inner product
• Inner Soddy circle
• Inradius
• Inscribed Angles
• Inscriptable (inscriptible) Polygons
• Integer
• Integer Iterations on a Circle
• Integral Domain
• Integration in Spherical Coordinates
• Intercept
• Intercepted Arc
• Interest Calculations
• Interior Angles formed by a secant and parallel lines
• Intermediate Value Theorem
• Internal point
• Internal Tangent to Two Circles
• Internet News sites
• Intersecting Chords (Secants) Theorem
  • Intersecting Chords Theorem
• Intersection of sets
• Intouch Triangle
• Invariant Set
• Inventor's Paradox
• Inverse Element
• Inversion (combinatorial)
• Inversion (geometric)
  • Inverse image
  • Inversion
  • Inversion Tool
  • Inversion with Negative Power
• Invert the Divisor and Multiply
• Involution
• Irrational Numbers
• ISBN Encoding
• Isogonal lines
  • Isogonal circle
  • Isogonal conjugates
  • Isogonal Conjugality
  • Isogonal Concurrency
• Isogonic Centers
• Isolated point
• Isometry
  • Plane Isometries
• Isosceles trapezoid
• Isosceles Tetrahedron
• Isosceles triangle
• Isotomic lines
• Isotomic conjugates
• Isoperimetric Inequality
• Isoperimetric Theorem
• Isoperimetric Theorem, a variation on
• Isoperimetric Theorem, a different one
• Iterative process

J

• Jam
• Japanese Theorem I
• Japanese Theorem II
• Jefferson's Method of Apportionment
• Joachimsthal's Notations
• John Sharp's Paradox
• Johnson-Trotter Method
• Jordan Curve Theorem
• Josephus Flavius, a legend and a problem
• Judd Illusion
• Julia sets
• Jump

K

• Kanizsa Triangle
• Kantor's Circle
• Kaprekar's constant
• Kaprekar's process
• Kayles
  • Grundy function for Kayles
• Kiepert's Theorem
• Kiepert's Perspector
• Kirkman's Theorem
  • Pascal Lines: Steiner and Kirkman Theorems II
• Kitaoka's waves
• Kite
• Klein Bottle
• Knots
• Koch's snowflake
• Koffka's Illusion
• Königsberg
• Königsberg Bridges
• Kronecker's symbol
• Kruskal's algorithm
• Kurschak's Tile and Theorem

L

• La Hire's Theorem
  • La Hire's Theorem, a Variant
  • Joachimsthal's Notations
• Labeling of a graph
• Lagrange's identity
  • Lagrange's identity, Proof
• Lagrange's polynomial
• Lambert's Theorem
• Langford Sequence
• Langman's Paradox
• Latin Squares
• Lattice
• Lattice
• Lattice Multiplication
• Latus Rectum
• Law of Cosines
• Law of excluded middle
• Law of Sines
• La Hire's Theorem
• Leaf
• Leap Year
• Least Common Multiple (lcm)
  • Algorithm for Computing LCM
• Left-handedness
• Leibniz Triangle
• Legendre's Lemma
• Lemoine antiparallel
• Lemoine circles
• Lemoine hexagon
• Lemoine line
• Lemoine point
• Léon Anne's theorem
• Leonardo's Claws
• The Lepidoptera of the Circles
• The Lepidoptera of the Quadrilateral
• Level Curve
• Levenshtein Distance
• Lewis Carroll's problem
• Lewis Carroll's Game of Logic
• Lexicographic order
  • Complex numbers
  • Permutations
  • Pigeonhole
• Lights Out
• Lindemann's Theorem
• Line at infinity
  • Line at Infinity
  • Line at infinity
• Linear combination
• Linear function
• Linear order
• Linear Programming
• Linear Space
• Linear Transformation
• Lines in general position
• Liouville's Theorem
• Listing all permutations
• Local-Global Principle
• Locus
• Logarithmic spiral
• Logistic equation
• Logistic model
• Logo of mine
• Lone Divider Method
• Long Multiplication
• Long Runs of Composite Numbers
• Looking your best
• Loop
• Looping Chips
• Lowest Terms, fraction in
• Loyd's Puzzles, Sam
  • Can you better Sam Loyd?
  • Farmer and Wife To Catch Rooster and Hen
  • Sam Loyd's fifteen
  • Sam Loyd's Geometric Puzzle
  • Plato's Geometric Numbers: can you better Sam Loyd?
  • Puzzlist vs. Mathematician: A Practical Arithmetic Problem
  • The Gordian Knot
• Lubell-Yamamoto-Meshalkin inequality
• Lucas' Theorem
  • Lucas' Theorem
• Lucky 7 puzzle.
• Lune
• LYM inequality

M

• Maclaurin series
• MacLaurin's Construction of Conics
• Magic in Square
• Magic Squares game
• Mahavira's theorem
• Major circle of ellipse
• Malfatti's Problem
• Maltitude
• Mandelbrot and Julia sets
  • Iterations and the Mandelbrot Set
• Mannheim's Theorem
• Manifesto
• Markers Method of Fair Division
• Marriage Theorem
• Mascheroni constructions
• MasterMind, Invitation to
• Material Point
• Mathematical Expectation
• Matrix
• A Matter of Age
• Maximal Chain
• Maximum Modulus Theorem
• Maxwell's Theorem
• Mazes
  • Mazes
• Mean Proportional
• Mean Value Theorem
  • Rolle's and Mean Value Theorems
• Mechanical Proof of the Pythagorean Theorem
• Medial triangle
• Median triangle
• Median
• Median Point
• Medians in a Quadrilateral
• Mediant fraction
  • Mediant fraction
  • Dots and Fractions
• Mendelsohn triple
• Menelaus Theorem
  • Menelaus is equivalent to Ceva I
  • Menelaus is equivalent to Ceva II
• Merlin's Magic Squares
• Metamathematics
• Metric Completeness
• Metric Function
• Metric Space
• Mex rule
  • Mex rule
• Midline (in a triangle)
• Millipede
• Mini Lights Out
• Minimal Lattice
• Minimal-change Property
• Minimax Principle
• Minimax Theorem
• Minimum element in a poset
• Minimum Spanning Tree
  • Minimum Spanning Tree
• Minkowski addition
• Minkowski subtraction
• Miquel's Point
  • Miquel's Point of a 4-line
  • Miquel's Point of a 4-line Via Spiral Similarity
• Mirror property of the orthic triangle
• Mirror property of the altitudes
• Mixed Product of Three Vectors
• Mixtilinear Circles and Concurrence
  • Radius and Construction of a Mixtilinear Circle
• Mobile Integer
• Model
• Modulo Arithmetic
  • Modular Arithmetic
• Modulus of a complex number
• Modus ponens
• Modus tollens
• Möbius Strip
• Möbius Transformations
  • Möbius Transformations
• Mohr-Mascheroni construction
• Monge Point
• Monge's Circle Theorem
  • Monge via Desargues
  • Monge via Desargues II
• Monic polynomial
• Monomino
• Monotone Convergence Theorem
• Monty Hall Dilemma
• Moore's Plane Filling Curve
• Morley's Miracle
  • Doodling and Miracles
• Most likely number of successes in Bernoulli trials
• Müller-Lyer Illusion
• Most elementary theorem of Euclidean geometry
• Multiplicand
• Multiplication
• Multiplicative Inverse
• Multiset
• Mutation
• Mutually Exclusive Events
• Mutually prime integers
• My logo

N

• 9-Point Center
• 9-Point Circle
  • 9-point Circle as a Locus of Concurrency
• Nagel Line
• Nagel Point
  • Nagel Point
• Nagel's Theorem
• Napier Bones
• Napoleon Points
• Napoleon's Theorem
  • Napoleon's Theorem, a generalization
  • Napoleon's Theorem by Plane Tesselation
  • Napoleon's Theorem, two proofs
  • Napoleon's Theorem, complex variables
  • Napoleon's Theorem, circle incidence
  • Napoleon's Propeller
• Near
• Necker Cube
• Negative Powers
• Neighborhood
• Nephroid
• Nested Radicals
• Neuberg's Theorem
  • Neuberg's Theorem, Synthetic proof
• Neusis Constructions
  • Neusis
• New-States Paradox
• Newton-Gauss line
• Newton's line
• Newton's Theorem
• Nim, the game of
• Nimble
• Nimber
• Nim-heap
• Nim-sum
• Nine-point Circle
• Nine dots problem
• n-Line
  • Characteristic Constants of the n-Line
• Nobbs' points
• Non-degenerate conic
• Non-Eclidean Geometries
• Nonseparable Graph
• Norm (of a vector)
• Normal play
• Normal topological space
• Northcott's game
• Nothing is something
• Nowhere dense set
• N-position
• Number Line
• Number Mosaics
• Number System With Base 36
• Numbers, types of
  • Numbers, Conway's definition
• Numeral
• Numerator

O

• 1-1 correspondence
• Obtuse angle
  • Obtuse angle
• Obtuse triangle
• Odd permutation
• Odd vertex
• Oddball Problem
• Old Japanese Theorem
• Olof Hanner's Jigsaw Puzzle
• One Pile
• One-sided surfaces
• Open interval
• Open sets
• Open walk
• Operations on Fractions
• Operator
• Oppositely Congruent Figures
• Optical Illusion
• Optical Property of Ellipse
• Orbison Illusion
• Orbits
• Order, Ordered Space
• Ordinary Generating Function
• Ordinate
• Orientation
• Origami
• Orthic Axis
• Orthic triangle
  • Mirror property of the orthic triangle
• Orthocenter
• Orthocentric system
• Orthodiagonal Quadrilateral
  • Orthodiagonal Quadrilateral
• Orthogonal latin squares
• Orthogonality
• Orthologic Triangles
• Orthopole
• Other math sites
• Outdegree
• Outer Soddy circle

P

• p-adic Expansions
• p-adic Numbers
• Pace
• Packing shapes in a plane
• Palindromic
• Paper Folding
• Paper strip activities
• Pappus' Generalization of Euclid I.47
• Pappus' Theorem
  • Dual to Pappus' Theorem
• Parabola
  • Parabola as locus
  • Parabolic Mirror
  • Parabola as Envelope
• Paradox
• Paradox of Tristram Shandy
• Parahexagon
• Parallel Lines
• Parallel Postulate
• Parallelogram
• Parallelogram Law
  • Parallelogram law
• Parallelogram rule
• Parametric Equation of a Straight Line
• Parity
  • Parity of a node on a graph
• Parpolygon
• Parrondo Paradox
• Partial order
  • Partial order in a lattice
• Partition of point sets in a plane
• Partitioning a Circle
• Partizan gameA second look
• Pascal's Identity
• Pascal's linePascal Lines: Steiner and Kirkman Theorems
• Pascal's theorem
  • Pascal's theorem
  • Pascal's Theorem, Homogeneous Coordinates
  • Pascal in a Cyclic Quadrilateral
  • Pascal in Ellipse
• Pascal Triangle and Sierpinski Gasket
  • Pascal Triangle and the Tower of Hanoi
• Peano axioms
• Peano Curves
• Peano and Wunderlich's Plane Filling Curves
• Peasant Multiplication
• Peaucellier Linkage
• Pedal circle
• Pedal curve
• Pedal point
• Pedal triangle
• Pedal Construction of Parabola
• Pedal Curve
• Pedoe's Theorem
• Peg Solitaire
  • Peg Solitaire and Group Theory
• Pencil of circles
• Pencil of lines
  • Munching on Inscribed Angles
• Penosculant
• Pentagon, construction of
• Percent
• Perfect Langford Sequence
• Perfect number
• Perimeter Splitter
• Periodic cycle
• Periodic patterns in sin(N)
• Permutation
  • How to define a permutation
  • Listing all permutations
  • What, how, and the Web
• Perpendicular bisector
• Perspective triangles
  • Triangles perspective from a point
  • Triangles perspective from a line
• Petersen Graph
• p
  • Determination of p
• Pick's Theorem
• Pigeonhole principle
  • Pigeonhole Principle and Extensions
• Pitot's Theorem
• Pivot Theorem
• Pivotal Player
• Place Value
• Plainim
• Plainim Misère
• Planar graph
• Planar polygon
• Plane Filling Curves
• Plato's Geometric Numbers: can you better Sam Loyd?
• Plane Isometry
• Plücker's Lines
• Plus or Minus
• Poggendorff Illusion
• Poggendorff Illusion II
  • Circular Poggendorff Illusion
• Point
• Point at infinity
  • Point at Infinity
  • Point at Infinity
  • Point at infinity
• Point Circle
• Point in a Square
• Point inside a triangle
• Point-Slope Equation of a Straight Line
• Polar Circle
• Polar coordinates
• Polar Equation of conics
• Pole and Polar with respect to an angle
• Pole and Polar with respect to a circle
• Pole and Polar with respect to a triangle
• Pole
• Poles and Polars
• Polygon
• Polygonal number
• Polyomino
• Pompeiu's Triangle and Theorem
• Poncelet's Porism
• Poncelet's Theorem
• Ponzo Illusion
• Ponzo Illusion II
• Population Paradox
• Porism
• Poset
• Positional Number System
• Positive (Counterclockwise) Direction
• Power of a point with respect to a circle
  • Power of a point with respect to a circle
• Power of Inversion
• P-position
• Predicate
• Prim's algorithm
• Prime
• Prime Number Decomposition
• Primorial
• Principal
• Principle of Conservation of Angular Momentum
• Principle of Duality
• Principle of Proportionality
• Prisoner's Dilemma
• Probability
  • Probability density function
  • Probability distribution function
• Probability paradoxes
• Product of Rotations
• Sequential Rule
• Proizvolov's Identity
• Projection
• Projective Geometry
• Projective Plane
• Pronk
• Proofs Without Words
  • Proof
• Proper Isometry
• Property of an
• Propositional Variable
• Protractor Postulate
• Ptolemy's Inequality
• Ptolemy's Theorem
  • Ptolemy's Second Theorem
  • Ptolemy's Theorem implies Pythagoras' Theorem
  • Sine, Cosine, and Ptolemy's Theorem
  • Euler's Generalization of Ptolemy's Theorem
• Pure existence proof
• Purely Imaginary Complex Numbers
• puz(G), the graph of a puzzle
• Puzzles on graphs
• Pythagoras' Theorem
  • Mechanical Proof of the Pythagorean Theorem
  • "Extra-geometric" proofs of the Pythagorean Theorem
  • Pythagorean Theorem, Generalizations of
• Pythagorean triples
  • Proof of the formula
  • Norm of Gaussian integers
  • Gaussian integers
  • Divisibilty in Pythagorean Triples
  • Trinary Tree(s) underlying Primitive Pythagorean Triples
• Q
  • Quadratic Average
  • Quadratic Field
  • Quadratic Formula
    • Completing a Square and Quadratic Formula
  • Quadratic Function
  • Quadrangle
  • Quadrilateral
  • Quarter-turn
  • Quasigroup
    • Quasigroups and block designs from triangular grid
  • Quota Rule
  • Math Quotations, a Web poll

R

• Rabinowitz's Point
• Radical axis of two circles
• Radical center of three circles
• Radius of Inversion
• Radius-vector
• Radix
• Ramsey Number
• Ramsey Theorem
  • Ramsey's Theorem is Sharp
• Random Dot Stereograms
• Random Event
• Random Number Generator
• Random Variable
• Rational approximation
• Rational integers
• Rational numbers
• Rational Root Theorem
• Ray
• Real numbers
• Real Part of a Complex Number
• Real Product of two Complex Numbers
  • Real Product of Complex Numbers
• Rectangle
• Recurrence relations
• Reflection
• Reflection in Line
• Reflection in Point
• Reflection Law in Ellipse
• Reflective Properties of Parabola
• Reflex angle
• Reflexivity
  • Reflexivity
• Regular polygon
• Regular polyhedron
• Relatively prime integers
• Removable singularity
• Repelling point
• Rep-tile
• Residue classes
• Retinend
• Reuleaux's triangle
• Reverse Solitaire
• Reversible move
• Revolving Circles Illusion
• Rhombus
• Riemann Sphere
• Right angle
• Right triangle
• Right-handedness
• Rigid motions
  • Rigid motion
• Ring
• Rolle's Theorem, the
  • Rolle's and Mean Value Theorems
• Rotocenter
• Rottary gallop
• Rounding numbers
• Rouse Ball's Fallacy
• Routh's Theorem
• Row vector
• Russell's Paradox
• Russian Peasant Multiplication
• Rusty Compass Construction of Equilateral Triangle

S

• 7 Coins Puzzle
• Sam Loyd's Puzzles
  • Can you better Sam Loyd?
  • Farmer and Wife To Catch Rooster and Hen
  • Sam Loyd's fifteen
  • Sam Loyd's Geometric Puzzle
  • Plato's Geometric Numbers: can you better Sam Loyd?
  • Puzzlist vs. Mathematician: A Practical Arithmetic Problem
  • The Gordian Knot
• Saddle Point
• Salinon: From Archimedes' Book of Lemmas
• Salmon's points
• Sam Loyd's fifteen
• Sam Loyd's Geometric Puzzle
• Sam Loyd's Son's Dissection
• Sangaku
• SaRD Construction
• SAS
• Sawayama's Lemma
• Scalar
• Scalar product
• Scalene triangle
• Schlafli formula
• Scintillating Grid Illusion
• Scoring
• Scoring Misère
• Scrub Tile Puzzle
• Sealed Bids Method
• Secant
  • Secant
• Secant Angles
• Second Napoleon Point
• Second Theorem of Apollonius
• Sector (in circle)
• See-Saw Lemma
• Segment (in circle)
• Self-conjugate triangle
• Self-descriptive Strings
• Self-documenting sentences
• Self-dual configuration
• Self-reference
• Semigroup
• Sending scouts into the desert
• Separating point sets with a circle
• Sequential Coalition
• Sequential compactness
• Sequential Rule
• Set
• Seven Circles Theorem
• Seven Terms Periodic Sequence
• Shaggy Dog Theorem
• Shape Property
• Shapes in a lattice
• Shapes of constant width
  • Star Construction of Shapes of Constant Width
• Shapley-Shubik Index
• Shearing Transform
• Shepard's Parallelogram Illusion
• Shift
• Shimmer Illusion
• Ship-Dock Theorem
• Shredding the torus
• Shuttle Puzzle
• Sibling node
• Sierpinski Carpet
• Sierpinski gasket
  • Dot Patterns and Sierpinski Gasket
  • Sierpinski Gasket by Trema Removal
• Sieve of Eratosthenes
• σ-Algebra
• Signed segment
• Signum function, sign(t)
• Silver Dollar Game
• Similar orderings
• Similar Triangles, theorem of
• Similarity
• Similarity dimension
• Simple continued fraction
• Simple graph
• Simple polygon
• Simplex
• Simson Line
  • Simson Line From Isogonal Perspective
• Simson-Wallace Theorem
• Simpson's paradox
• Simultaneous Contrast Illusion
• Simultaneous Contrast Illusion II
• Sine Law
• Single formula to express any integer with digits 0-9 each used just once
• Six Circles Theorem (Elkies)
• Six Circles Theorem (Evelyn)
• Skolem Sequence
• Slider Puzzles
• Sliders
• Slope
• Slope-Intercept Equation of a Straight Line
• Social Choice
• Soddy circles
• Soddy Line
• Soddy points
• Solitaire in the Circle
• Somos-4 Sequence
• Soriteses
• Soroban
• Sorting Algorithms
• Spanning Tree
• Sperner's Labeling
• Sperner's Lemma
• Sperner's Theorem
• Sphere
• Spieker Center
• Spira Mirabilis
• Spiral Similarity
  • Miquel's Point of a 4-line Via Spiral Similarity
• Splitter
• Splitting piles
• Sprague-Grundy function
• Square
• Square numbers
• Squaring a circle
• Squaring Parabola
• Squares and Circles
• Squares, Circles, and Triangles
• Squinting Eyes Theorem
• SSS
• Stability
• Staircase Illusion
• Star Polygons
• Star-shaped region
• Stationary point
• Steiner Porism
  • Steiner Porism
• Steiner's Circle
• Steiner's Curve
• Steiner's Theorem
• Steiner's and Kirkman's Theorems
  • Pascal Lines: Steiner and Kirkman Theorems II
• Steinhaus' Problem
• Stereographic projection
  • Stereographic Projection and Radical Axes
• Stern-Brocot Tree
  • Binary Encoding with the Stern-Brocot tree
• Stern's diatomic series
• Stewart's theorem
• Straight angle
• Straight Edge Only Construction of Polar w.r.t. an Angle
• Straight Edge Only Construction of Polar w.r.t. a Circle
• Straight line
• Straight Tromino
• Strategy stealing in the game of Hex
• Stretching
• Suan pan
• Subfactorial
• Subgraph
• Subgroup
• Subjective contour
• Subtraction Game
• Successor
• Sum Rule
• Sums and Products
• Superfactorial
• Supergraph
• Superposition Principle
• Supplementary angles
• Supporting lines of convex figures
• Surjective function
• Surreal numbers
  • Surreal Numbers
  • Surreal numbers and games
• Syllogism, Modes Ponens
  • Syllogism, more general
• Symmedian
• Symmedian point
• Symmetric difference
• Symmetric group
• Symmetric relation
• Symmetry in circle
• Synthetic division
• System of Distinct Representatives

T

• 3-4-5 triangle
• 3 glass puzzle
• 3 glass puzzle, second, more general tool
• T-Junction
• Take-Away Games
• Tangent Pair
• Tangent to two circles
• Circle of Similitude
• Tangential triangle
• Tarski-Banach Decompositions
• Taylor circle
• Taylor series
• Telescoping Series
• Ternary number system
• Tessellation
• Tesseract
• Thales' Theorem
• Thales' Theorem

• The only rational triangle
• The Two Men of Tibet Problem
• Thébault's Problem I
• Thébault's Problem II
• Thébault's Problem III
• Theorem of Complete Quadrilateral
• Theorem of Theaetetus
• Thick set
• Thin set
• Third Proportional
• Three pancakes problem
• Three 3s
• Three 4s
• Three 5s
• Three Circles and Common Tangents
• Three circles problem
• Three Tangents Theorem

• Three Tangents Theorem

• Toads And Frogs Puzzle
• Toothpick Construction of a Square
• Topological equivalence
• Topological Space
• Topological transformation
• Topology
• Torque
• Torricelli point">
• Torus
• Totality (of a binary relation)
• Totally ordered set
• Tower of Hanoi

1. Sierpinski Gasket and Tower of Hanoi
2. Bicolor Towers of Hanoi

• Toys and Tots problem
• Trachoids
• Train wheel quandary
• Transcendental numbers
• Transfinite Cardinality
• Transitive groups
• Transitivity in Action

• Transivity

• Translation Transform
• Transpose of a vector
• Transposition

• What, how, and the Web

• Transversal
• Transverse gallop
• Trapezoid
• Tree
• Trefoil knot
• Trema
• Triangle Classification
• Triangle Inequality, the

• Axioms of distance function
• Absolute Value of Complex Number

• Triangle of Similitude
• Triangular Billiard
• Triangular numbers

• There exist triangular numbers that are also square

• Triangulation

• Diagonal Triangulation

• Trichotomy, the law of
• Trigonometric Form of Ceva's Theorem
• Trigonometric Form of Complex Numbers
• Trilateral Diagrams
• Trilinear Coordinates
• Trivial Ramsey Number
• Tromino

• Straight Tromino

• Trot
• Tucker Circles
• Turn
• Turning Turtles
• Tweedledum & Tweedledee Principle
• Twin Circles of Archimedes
• Twisted Cord Illusion
• Two Butterflies Theorem

• Two Butterflies Theorem II

• Two coins puzzle
• Two Envelopes Paradox
• Two Numbers Guessing Game
• Two-squares identity

U

• Uniform convergence
• Uniform probability distribution
• Union of sets
• Unique Factorization Theorem
• Uniqueness of number 30
• Unit element
• Unit Fraction
• Unity
• Universal Quantifier
• UPC-A encoding
• Urquhart's Theorem
  • Urquhart's Theorem
• V
  • Value
  • Van Obel Theorem, Determinants, and Barycentric Coordinates
    • Gergonne and Van Obel Theorems
  • Van Aubel's theorem
  • Van Schooten's theorem
    • Van Schooten's and Pompeiu's Theorems
  • Varignon Parallelogram
  • Vecten's Collinearity
  • Vecten configuration
  • Vecten Points
  • Vector
  • Vector product
  • Vector Space
  • Venn Diagrams
  • Verging
  • Versine
  • Vertex
  • Vertical Angles
  • Vi�te's Formulas
  • Viewing a Statue
  • Viviani's Theorem
• W
  • Walk on a graph
  • Wallace-Bolyai-Gerwien Theorem
  • Wallace's Theorem
  • Wasan
  • Web poll
  • Webster's Method of Apportionment
  • Weierstrass-Bolzano property
  • Weierstrass Product Inequality
  • Weighted graph
  • Weird curves bound normal areas
  • Weitzenböck Inequality
  • Well-ordered set
  • What do you call a centipede?
  • White's Illusion
  • Whole number
  • Whole part function, [x]
  • Wilson's Theorem
  • Wittenbauer's Parallelogram
  • Word Ladders
  • Word Problems
  • Wunderlich's Plane Filling Curves
  • Wundt Illusion
  • Wundt Block Illusion
  • Wythoff's Nim
  • Wythoff's Nim II
• X
  • XOR
  • X-intercept
• Y
  • Y Can't End in a Draw
  • Y-intercept
  • Y. Sawayama's Lemma
  • Yosan
• Z
  • 0!=1
  • Zaslavsky's theorem
  • Zeckendorf's theorem
  • Zenodorus Theorem
  • Zero
  • Zipf's Law
  • Zöllner's Illusion