Comment by card_zero

I was saying two separate things. Thing 1, the non-square shapes are relevant to Einstein's nice proof. Thing 2, considering squares now if you like, pythagoras's theorem has a magical quality which proofs can't dispel.

If you travel some distance, square it, travel some other distance perpendicularly, square that too, and add the results, you get the square of the straight distance from start to finish. Every proof just seems like a reformulation of this freaky fact.