a rectangle constructed starting with a regular dodecahedron
Source: Brazilian Mathematical Olympiad 1984 P3
July 27, 2018
geometryrectangledodecahedronregular polygon3D geometry
Problem Statement
Given a regular dodecahedron of side . Take two pairs of opposite faces: and . For the pair take the line joining the centers of the faces and take points and on the line each a distance outside one of the faces. Similarly, take and on the line joining the centers of each a distance outside one of the faces. Show that is a rectangle and find the ratio of its side lengths.