We are surrounded by shapes and figures. Almost everything solid has a shape. A ball is round, a coat hanger is a triangle and this table for instance has a rectangular form. But does shape really matter? Are shapes just a designer’s random idea or purposely selected elements?
Let’s look at manholes for instance. Most of the manholes that we encounter on the street have a circular shape. The reason for this lies in the physics behind the circle. A circle by definition has a constant diameter regardless of the way you measure it or in other words a curve of constant width. Other basic forms like triangles or squares have different diameters depending from which points we measure them.
So why a circular manhole? Simply explained, a square manhole cover could fall into the hole if the short edge of the cover were to line up with the longer diagonal diameter of the hole. By using a curve with a constant width we can prevent accidents from happening.
Are there any other curves of constant width that you know of?