I think that Tangram Puzzles are pretty neat. Once in a while I try to figure out how to create certain images/shapes that I see online. But my students don't really enjoy this activity. And I can't argue with them. There is a reason I only sit down and try it once in a while.
However, I did create an activity where students will use tangrams and trigonometry to create a certain image. I will apologize that they are hand-written, but I wrote these years ago and never had the energy to type them.
Tangram Activity Link