Uploaded June 2014 | Updated September 2026, 2 weeks ago
Every solid segment shown on this video maintains a constant length, yet the figure is able to deform, showing that convexity is essential in Cauchy's theorem on the rigidity of polyhedra. The hexagon formed by the gray segments has equal sides and equal angles (constantly right angles). The red and green triangles are equilateral. The whole figure is reminiscent of cyclohexane (but with different angles).
Every solid segment shown on this video maintains a constant length, yet the figure is able to deform, showing that convexity is essential in Cauchy's theorem on the rigidity of polyhedra. The hexagon formed by the gray segments has equal sides and equal angles (constantly right angles). The red and green triangles are equilateral. The whole figure is reminiscent of cyclohexane (but with different angles).
