Folding a Strip into a Pentagon
You are given a paper strip with 12 special triangles grouped in trapezoids. Fold over the larger diagonals of the trapezoids to form a regular pentagon.
 P. Hilton and J. Pedersen, Build Your Own Polyhedra, Menlo Park, CA: Innovative Learning Publications, Addison-Wesley Pub. Co., 1994 pp. 18–23.