Work out euler formula for polyhedra instantly with clear inputs, formula shown and shareable results.
For every convex polyhedron Euler's formula gives V − E + F = 2. Other values of the characteristic indicate a surface with holes: a genus-g surface has χ = 2 − 2g, so a torus-like polyhedron gives χ = 0.
Euler's polyhedron formula
V − E + F = 2
Genus
χ = 2 − 2g
Yes: 8 − 12 + 6 = 2.
Each edge is shared by exactly two faces, so summing sides over all faces double-counts every edge.