GKMS aperiodic monotile

The , or the hat, is a polygon, which along with it's mirror image can tessellate the plane, but only aperiodically. This makes it a solution to some formulations of the einstein problem. It can be formed as an outer-blend of eight 60&deg;-90&deg;-120&deg;-90&deg; kites, or 4 mirror-symmetric pentagons.