A polyhedral bitorus
A polyhedron that is a surface of genus 2. Surfaces of genus 2 can be visualized as doughnuts with 2 holes or as spheres with 2 handles.
In this polyhedron Euler’s relation doesn’t hold, instead we have Vertices - Edges + Faces = -2.
© matematita
The image belongs to the sections...:
The double torus (Topology)
Polyhedra of positive genus (3D geometry)