3 - Platonic solids previous next

There are only five solids with each edge the same length, each angle equal, and each corner alike:

Tetrahedron Octahedron Icosahedron Hexahedron
or Cube

These are called regular polyhedra, or
Platonic solids.

These pictures are from the Wikipedia article on Platonic solids. Permission to use them was granted under the GNU Free Documentation License.