Help us caption and translate this video on Amara.org: http://www.amara.org/en/v/B2vR/ Esercizi: http://www.khanacademy.org/exercise/herons_formula Traduzione in Italiano del video Part 2 of the Proof of Heron's Formula http://www.youtube.com/watch?feature=player_embedded&v=nZu7IZLhJRI http://www.khanacademy.org/video/part-2-of-the-proof-of-heron-s-formula?playlist=Geometry Help us caption & translate this video! http://amara.org/v/B2vR/