Inspired by this thread on /r/math ==> http://redd.it/vzqzj
This comment has some interesting links and further readings: http://www.reddit.com/r/math/comments/vzqzj/explain_this_for_me_please_as_simply_possible_im/c590w2t
Apparently this started as a dinnertime conversation with Richard Feynman: http://frink.machighway.com/~dynamicm/feynman.html
According to R.J. Cook & G.V. Wood (2004). Feynman's Triangle. Mathematical Gazette 88:299-302, this triangle result puzzled famous physicist Richard Feynman in a dinner conversation: For a triangle ABC in the plane, if each vertex is joined to the point (1/3) along the opposite side (measured say anti-clockwise), then area ABC = 7 x area UWV (the inner triangle formed by these lines).