There are two shawls, one in the shape of a square, the other in the shape of a regular triangle, and their perimeters are the same. Is there a polyhedron that can be completely pasted over with these two shawls without overlap (shawls can be bent, but not cut)? (S. Markelov).
Problem
Source: 2008 Oral Moscow Geometry Olympiad grades 10-11 p5
Tags: geometry, polyhedron, 3D geometry