Truchet polygons

Truchet tiles are square tiles with quarter-circles on opposite vertices. When you put several tiles together, the circles line up. You can extend the idea to any even-sided regular polygon.

There are, as far as I know, only four tilings of the plane with even-sided regular polygons.

This was inspired by Colin Beveridge's article in Chalkdust magazine, Too Good to be Truchet. I haven't actually read the article yet, only the title...