Above: A fractal Africa, by Iranian mathematical artist Naderi Yeganeh. The areas of the octagons in adjacent tiers stand in the golden ratio, and their numbers increase according to the Fibonacci sequence.

Below: A tessellating Texas, by Wikimedia user Anachronist. “After having seen a plaza using Texas-shaped flagstone tiling many years ago, I decided to reproduce this tessellation.” Each Texas shape is a 12-sided polygon.