The pattern in the challenge results in a figure called Sierpinski's triangle, named after the Polish mathematician Waclaw Sierpinski, who developed it in about 1915.

Parts of some fractals look like the whole fractal. This property is called self-similarity.

Figures that can be built with smaller copies of the same figure are sometimes called rep-tiles or clones.

Some computer illustrations use fractals to model clouds, coastlines, and mountains.