I'm giving a presentation on Green's theorm for class, and someone gave me this article that pretty much tells you how green's theorem work. It starts with 2 squares, and then you combine to square to form a rectangle, and then when you add the double integeral, line integeral, and the paths cancel, leaving the integeral around the rectangle. it has a lot of descriptions, such as if I draw a half circle on top of the square, and I add the integeral, it will cancel, and again, give the perimeter. so basically it concludes that if greens theorem holds for individual shapes(square, triangel, triangle w/ curvy hypotnuse), then it will hold for entire region. then it goes to prove for the shapes. I can't find a site that actually does all the proof in a "proof like" manner. and for my presentation, I would also like to draw the diagrams, but I dont want to mess up. I would rather quote from someone rather then do it myself....does anyone have any sites or know any sites that have a better visual proof of this for green's theorem?