Tiling with pentagons - math news

Here's a well-written article (and easy to read even for laypeople) about a century-old math problem that has finally been solved. It has to do with tiling the plane with PENTAGONS.

In a nutshell, there are ONLY 5 families of convex pentagons that tile the plane. The situation is altogether different, and much easier, for rectangles, triangles, and quadrilaterals.

The article explores and explains these concepts in an easy-to-follow manner and with wonderful graphics. Tilings are something easy to understand, yet when it came to pentagons, the situation turned to be very complex.

This second link shows an image of the 15 families of pentagons that tile the plane.