The properties of solid figures have kept mathematicians occupied for centuries. Polyhedra are formed from regular polygons such as squares or triangles and mathematicians have failed to find any more than five of them.
Although they were defined by Pythagoras two hundred years before PLATO was born, they are known collectively as the platonic solids, named in honour of Plato by the geometer Euclid.
“THE PLATONIC SOLIDS – The regular polyhedron is defined as a three-dimensional solid comprising regular polygons for its surfaces – and with all its surfaces, edges and vertices identical. The five regular polyhedra are the tetrahedron (four triangular faces), the cube (six square faces), the octahedron (eight triangular faces), the dodecahedron (twelve pentagonal faces) and the icosahedron (twenty triangular faces).”
- the-golden-ratio-and-astronomy (blogs.stsci.edu)