High Quality Content by WIKIPEDIA articles! If the regular poyhedra are considered as skeletal 3-dimensional figures with flexible vertices and unidimensional edges, two of them. the hexadron(cube) and the dodecahedron exhibit properties different from the other three in that they can be folded or collapsed; The hexahedron first into a double square then a line. and the dodecahedron into a triangle. This can be demonstrated by constructing them out of drinking straws and twistable inserts.