Pythagorean Spiral
Play with mine or make your own.
Inspired by Mel Bochner's Pythagoras (4)
http://www.wikipaintings.org/en/mel-bochner/pythagoras-4-2006
via http://arithmetical-design.tumblr.com
More GeoGebra at mathhombre.blogspot.com
Think aloud about this sketch at http://mathhombre.blogspot.com/2013/02/pyth-on.html