Tessellation originally referred to the making of mosaic patterns, arranging square tiles to make an artistic design. Now it is used of any arrangement into patterns of regular shapes. A square is the easiest shape to tessellate, and if you have enough in lots of contrasting colours you can make a design similar to those popular in the Byzantine period of the Roman Empire.

Another effective shape for tessellation is the equilateral triangle, whose sides are equal, and angles equal. If you arrange six equilateral triangles round a central point you get a regular hexagon, the shape bees use when making a honeycomb.

When builders use bricks to build a wall, they tessellate them in the way that gives the greatest strength, called a bond. They make the point where two bricks are placed end to end come at the middle of the bricks above and below.

At any point where several tiles meet the angles will add up to 360°. So six angles of 60°, four of 90°, or three of 120°, are good shapes to tessellate (using equilateral triangles, squares, and hexagons). But with five shapes to fit round a single point, the angles will be 72°, as with Isotiles.