Tessellating Capitals

Stage: 1 Challenge Level: Challenge Level:2 Challenge Level:2

It might be a good idea to have a letter cut out of card to use as a template to draw around. Or you could cut out lots of the same letter and rearrange them to make a tessellation. Here are some letters which you could print off and cut out to get you started.
When you are designing a new letter to try, what will you need to think about so that it will tessellate?