A polyhedral torus
A polyhedron that is homeomorphic to a torus; for this polyhedron Euler’s relation does not hold. Instead we have: Vertices - Edges + Faces = 0
You can see also a net.
© matematita
The image belongs to the sections...:
From "fragments of topology" (From "XlaTangente")
The torus (Topology)
Euler relation (3D geometry)
Polyhedra of positive genus (3D geometry)