Garfield's proof for pythagorean theorem
(an algebraic proof for pythagorean theorem)
at first i made this applet on February 2008
then i remade it as a video (you can see it here: [url]http://www.geogebratube.org/material/show/id/44977[/url])
on January 2011
this is the final version (as a non interactive presentation)
Thessaloniki (Macedonia-Greece)
August 2013
