The problem of the three houses on a torus
The problem of the three houses on a torus. You can see other versions of the problem.
You can also try to solve this problem online with the interactive animation Paths without crossings.
Exhibit of matemilano, section "Topology".
The image belongs to the sections...:
From the exhibition matemilano (Topology)
Jordan's theorem and the three houses problem (Topology)
The torus (Topology)
Images from the topology section (From the exhibitions of matematita)