What are the names of the shapes?

Answer 1

The names of common 2-dimensional geometrical shapes:

No straight sides

circle (constant diameter)

ellipse, oval (varying width)

Three or more straight lines (polygons) --

3 sides

triangle

4 sides (quadrilaterals)

square (4 equal sides, right angles)

trapezoid (4 sides with only 1 set of parallel lines)

rectangle (4 sides with 2 sets of parallel lines)

rhombus (4 sides, 2 parallel pair)

5 sides - pentagon

6 sides - hexagon

7 sides - heptagon (rarely septagon)

8 sides - octagon

9 sides - enneagon (classically - nonagon)

10 sides - decagon

11 sides - hendecagon (classically - undecagon)

12 sides - dodecagon (classically - duodecagon)

13 sides - tridecagon or triskaidecagon

14 sides - tetradecagon

15 sides - pentadecagon

16 sides - hexadecagon

17 sides - heptadecagon

18 sides - octadecagon

19 sides - enneadecagon (nonadecagon)

20 sides - icosagon

30 sides - tricontagon

1000 sides - chiliagon

10000 sides - myriagon

1000000 sides - megagon

The names of some 3-dimensional shapes (solids)

sphere - 3-dimensional circle

spheroid, ellipsoid - 3-dimensional curved shape with oval cross sections

cylinder - circle/oval extended in one direction, with 2 spheroid ends

cone - circular base, constant triangular cross section

-(created by rotating a triangle about a bisector)

spiral a flat curve

helix a risen curve

Shapes with flat planar sides (polyhedrons, polyhedra) --

pyramid - solid with 3 or more triangular faces, any number of sides for a base

tetrahedron - four triangular faces

pentahedron - 5 faces (square pyramid, prism)

cube - 3-dimensional square, 6 faces