From a decagon to a bitorus
How to get a bitorus from a decagon: this is the third step. Here you can see the fourth step and the second one.
© matematita
immagine di Gian Marco Todesco
The image belongs to the sections...:
The double torus (Topology)
Surfaces obtained from a rectangle (Topology)
Further information:
http://www.toonz.com/personal/todesco