Platonic Solids

The Platonic solids are regular 3-D figures. Regular means that all the edges are of equal length, all the angles of equal measure, and all faces are congruent shapes. The solids were discovered by the Pythagoreans but later described by the Greek philosopher Plato.
Tetrahedron Hexahedron Octahedron Dodecahedron Icosahedron

Made of 4 equilateral triangles

It has the smallest volume for its surface

Made of 6 squares

Commonly called a cube

Made of 8 equilateral triangles

It rotates freely when held by two opposite vertices

Made of 12 equilateral pentagons

Made of 20 equilateral triangles

It has the largest volume for its surface area

Images by Rüdiger Appel