A Peculiar Geometric Property of Rounded Shapes

Jul 14, 2020

In our daily life, if something needs to be moved, designers prefer a shape that has a curve of constant width. For instance, while you are driving a car, you want a smooth drive. Or, you never wish to a manhole cover fall through its circular opening. It is an interesting fact that if a manhole cover is not a rounded shape, it could fall in the hole if it were inserted diagonally in the hole.

If you want to learn the unique geometry behind that fact, you can watch Marc Chamberland's beautifully illustrated video, "Why are manhole covers round?"