Proving Pythagoras' theorem

A few activities on the theme of proving Pythagoras’ theorem, including a version of Perigal’s dissection I took from another TES user.

The intention is to encourage discussion about what proof is, and to move pupils from nice-looking but hard to prove dissections to a proof they can make using relatively simple algebra (expanding and simplifying a double bracket).

Please review if you use it, like it or even hate it!