"Girih tiles have interior angles that are multiples of π/5. In the examples shown here I’ve applied the girih concept to polygons with angles that are multiples of π/7."

By Joe Bartholomew

Kürschák's Dodecagon

A visual proof by Kürschák that a regular 12-sided polygon inscribed in the unit circle has area 3. This means that estimating π to be 3 is like saying a circle is a Dodecagon.