Definition:Platonic Solid

Definition
Let $P$ be a convex polyhedron.

A platonic solid is a convex polyhedron:
 * $(1): \quad$ whose faces are congruent regular polygons
 * $(2): \quad$ each of whose vertices is the common vertex of the same number of faces.

That is, a platonic solid is a convex regular polyhedron.

Also known as
Some sources refer to a Platonic solid as a '''regular polyhedron.

However, the latter term technically also encompasses polyhedra that are not convex.

Also see

 * Five Platonic Solids