Saw a version of this as a gif on Tumblr, [br][url]http://curiosamathematica.tumblr.com/post/61569644908/twoblueeinsteins-animated-proof-of-the[/url],[br]and had to dynamicize it.[br][br]Now we can see it works for any two squares, which means any right triangle. Right?

More GeoGebra at [url]mathhombre.blogspot.org[/url]