Nets and tabs

Extract

There are some surprising connections between properties of solid convex polyhedra and the “nets” which can be used to make their shapes. These connections may be used as a starting-point for some interesting classroom investigations to “spot the pattern” or “guess and test”.

For a convex polyhedron, such as the pyramid shown below on the left, Euler's relation says that

Vertices + Faces = Edges + 2