Bibi Khanun mosque - gear pattern - ks
![Image](https://www.geogebra.org/resource/srndhrtd/7UMiiUwPq75WAAUk/material-srndhrtd.png)
In this pattern squares are arranged to form a gear. Four of these gears form a whole around a small empty square. In the gears you can read 4 times Allah and 4 times Ahad (one) lezen alike in the earlier described square pattern.
The applet below shows the construction of the tiling, starting from two squares arranged against each other.