The Platonic solids are regular 3D 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  Made of 6 squares  Made of 8 equilateral triangles  Made of 12 equilateral pentagons  Made of 20 equilateral triangles 
Smallest volume for its surface  Commonly called a cube  Rotates freely when held by two opposite vertices  Largest volume for its surface area 
Images by Rüdiger Appel