4 ms·

The diagrams on the pages shown basically serve as a proof.

• theoh 10y ago
  It's familiar from hands-on science museums to see a particular case of the Pythagorean theorem illustrated concretely with diagrams or liquid on a rotating plexiglass panel... But surely those aren't proofs, just illustrations. A proof needs to abstract over all possible right-angle triangles.
  • greglindahl 10y ago
    Both diagrams are a proof over all right-angle triangles, if you know algebra. See the very first comment after the images.
    • theoh 10y ago
      Hmmm. Maybe I'm just used to the convincing generality of the similarity argument (from Euclid, via Polya): https://math.berkeley.edu/~giventh/papers/eu.pdf https://math.berkeley.edu/~giventh/papers/eu.pdf But also, we can't trust geometrical diagrams: https://en.wikipedia.org/wiki/Missing_square_puzzle https://en.wikipedia.org/wiki/Missing_square_puzzle