Euler characteristic
Polyhedra
Columns: Name | Vertices V | Edges E | Faces F | Euler characteristic: V − E + F
Tetrahedron | 4 | 6 | 4 | 2 | Hexahedron or cube | 8 | 12 | 6 | 2 | Octahedron | 6 | 12 | 8 | 2 | Dodecahedron | 20 | 30 | 12 | 2 | Icosahedron | 12 | 30 | 20 | 2