Pythagorean Theorem is something that I think has to be practiced to get the hang of. My students always seem to have a hard time figuring out which side is missing.
I came up with this idea to try to get them to see it better. Having a right triangle that they can turn and manipulate helps them in identifying the missing side.
It is so fun folding, unfolding, turning, and folding some more, they forget they are working LOTS of problems! I even have students say this is fun. What could be better than that?!