Many pattern blocks use the same shapes as the pieces in tangrams -
One can buy sets of them from educational places that sell 'math manipulatives'
One place one can get them:
I think it's fun to play around with the pieces.
It's even more fun to let the grand kids play with them - because they have so much more imagination than I have!
Just had another thought - these pieces are plastic about 1/8 inch thick - wonder how they would work as templates if I ever got a hankering to do things the very old fashioned way - trace around a pattern, etc.