The Platonic Solids belong to the group of geometric figures called polyhedra.
A polyhedron is a solid bounded by plane polygons. The polygons are called faces; they intersect in edges, the points where three or more edges intersect are called vertices.
A regular polyhedron is one whose faces are identical regular polygons. Only five regular solids are possible
cube tetrahedron octahedron icosahedron dodecahedron
These have come to be known as the Platonic Solids