A Nice Visual way to prove some mathematical formulas

Here is a link to the BLOG by Bill The Lizard describing six visual proofs for some mathematical Algebra formulas:

http://www.billthelizard.com/2009/07/six-visual-proofs_25.html

Some other interesting links, i found:

http://www.billthelizard.com/2009/12/math-visualization-x-1-2.html

http://www.catonmat.net/blog/visual-math-friday/

Some other visual puzzles:

http://www.billthelizard.com/2009/07/how-many-squares-are-there-on-chess.html

http://www.billthelizard.com/2009/08/how-many-triangles.html

http://www.research.att.com/~njas/sequences/index.html