A dodecahedron is the name given to a polyhedron made up of 12 equal pentagons. It is one of the five Platonic solids: a group of regular, convex polyhedrons made up of congruent, polygonal faces.
The other Platonic solids are the tetrahedron, made up of 4 triangles; the hexahedron, made up of 6 squares; the octahedron, made up of 8 triangles; and the icosahedron, made up of 20 triangles. These shapes have been recognized as special since antiquity. Mathematicians and philosophers have long admired them for their symmetry and mathematical beauty. Role-playing games sometimes use dice made in the shapes of the five Platonic solids.