Pythagoras of Samos.
http://wiki.answers.com/Q/Who_said_a2_b2_c2

In mathematics, the Pythagorean theorem or Pythagoras' theorem is a relation in Euclidean geometry
http://www.chacha.com/question/whatisa2%2Bb2%3Dc...

Colorado Center for Biofuels and Biorefining (research center of Colorado Renewable Energy Collaboratory)
http://acronyms.thefreedictionary.com/C2B2

Differentiate it w. r. t. what?
http://answers.yahoo.com/question/index?qid=201111...
