The 13 books of Euclid's Elements are generally referred to by their book number.
The main subject matter of each book:
Book 1 contains the basic properties of geometry: the Pythagorean theorem, equality of angles and areas, parallelism, the sum of the angles in a triangle, and the three cases in which triangles are "equal" (have the same area).
Book 2 is commonly called the "book of geometrical algebra," because the material it contains may easily be interpreted in terms of algebra.
Book 3 deals with circles and their properties: inscribed angles, tangents, and the power of a point.
Book 4 is concerned with inscribing and circumscribing triangles and regular polygons.
Book 5 is a treatise on proportions of magnitudes.
Book 6 applies proportions to geometry: Thales' theorem, similar figures.
Book 7 deals strictly with elementary number theory: divisibility, prime numbers, greatest common divisor, least common multiple.
Book 8 deals with proportions in number theory and geometric sequences.
Book 9 applies the results of the preceding two books: the infinitude of prime numbers, the sum of a geometric series, perfect numbers.
Book 10 attempts to classify incommensurable (in modern language, irrational) magnitudes by using the method of exhaustion, a precursor to integration.
Book 11 generalizes the results of Books 1-6 to space: perpendicularity, parallelism, volumes of parallelepipeds.
Book 12 calculates areas and volumes by using the method of exhaustion: cones, pyramids, cylinders, and the sphere.
Book 13 generalizes Book 4 to space: golden section, the five regular (or Platonic) solids inscribed in a sphere.
euclids elements
There are 13 books in Euclid's Elements.
eetrgrv
i think that euclids elements were everything we know about geometry and that we will soon know a lot more about this subject because we are finding new things every day and soon someone will find out something new about geometry
There are 13 books making up Euclid's 'Elements'.
euclids elements
There are 13 books in Euclid's Elements.
Regular solids
His mathematical books called Elements. His work on geometry, particularly his famous axioms.
'Elements' was written by Euclid.
compositions
euclids elements
The thirteenth book in Euclids Elements has no specific title, but covers the Pythagorean proofs of Theaetetus (c. 417-369 bc) and the construction of the five regular Platonic solids (pyramid, cube, octahedron, dodecahedron, icosahedron) inside a given sphere.
need a simple explanation of Euclids theory.
In titles of books
Titles of books and periodicals should be put in italics.
eetrgrv