The five Platonic solids, also known as the five regular solids, were
discovered in ancient times. Although each one was probably known prior to
500 BC, they are collectively named after the ancient Greek philosopher Plato
(428-348 BC) who mentions them in his dialogue Timaeus, written circa 360 BC.
Each Platonic solid uses the same regular polygon for each face, with the same
number of faces meeting at each vertex. The five Platonic solids are the only
convex polyhedra that meet these criteria.