Tetrahedron is a Platonic solid. A Platonic solid is a convex polyhedron that is regular. It means that the faces of a Platonic solid are congruent regular polygons, with the same number of faces meeting at each vertex; thus, all its edges are congruent, as are its vertices and angles.
There are five more Platonic solids. They are Tetrahedron, Cube (or hexahedron), Octahedron, Dodecahedron and Icosahedrons.
(V - E + F)
For a regular tetrahedron of edge length a:
Base plane area = A0 = ?3 a2 /4
Surface area = A = 4 A0 = ?3 a2
Height = h = ?6a /3
Volume = V = A0h /3 = ?2 a3/12