Have you ever wondered why the cover of a manhole is nearly always round? Why isn’t it oval or square? Reuleaux curve based on an equilateral triangle. Reuleaux curves based on the pentagon (top) and ...

Several years ago, retired military officer Guan Baihua invented what may be the ultimate geometry geek bicycle. The front wheel is a pentagonal curve, and the back wheel is a reuleaux triangle (a ...

If you need something to roll smoothly along the ground, you better strap some of those circular things called wheels to it, right? Well, not quite—because there are actually other shapes that roll ...