Euclid's proof of Pythagoras' theorem

This is an illustration of the classical proof of [b]Pythagoras' theorem[/b].[br]There are many other proofs, but this is the one from [b]Euclid[/b].
Euclid's proof of Pythagoras' theorem
Play around with the vertices, A, B & C.[br]Can you describe carefully the construction shown here?[br]Why are the four coloured triangles equal in area (green=yellow=pink=blue)?[br]Can you find a rectangle having the same area as the square BCIH?[br]How can you conclude that [math]|AB|^2 = |AC|^2+|BC|^2[/math]?

Information: Euclid's proof of Pythagoras' theorem