The polyhedral formula generalized to a surface of genus ,
where is the number of polyhedron vertices, is the number of polyhedron edges, is the number of faces, and
is called the Euler characteristic.
The polyhedral formula generalized to a surface of genus ,
where is the number of polyhedron vertices, is the number of polyhedron edges, is the number of faces, and
is called the Euler characteristic.
Weisstein, Eric W. "Poincaré Formula." From MathWorld--A Wolfram Web Resource. https://mathworld.wolfram.com/PoincareFormula.html