Net of a polyhedron

Summary

A net of a polyhedron is a flat polygon that folds up into the surface of the polyhedron. It is made of the faces of the polyhedron, joined along some of their edges. It arises by cutting the surface along a spanning tree of edges and unfolding it into the plane without overlap. Nets are used to build paper models, and whether every convex polyhedron has one is the open Dürer's conjecture.