This illustrates Maekawa's Theorem in the mathematics of paper folding. It replaces Lang rule two.png which has the folds wrong and isn't well named plus this is a svg instead of a png.
<a href="//commons.wikimedia.org/wiki/User:Dmcq" title="User:Dmcq">Dmcq</a>
CC BY-SA 3.0
<span class="int-own-work" lang="en">Own work</span>