Rivers(futilitycloset.com)
57 points by surprisetalk | 5 comments
57 points by surprisetalk | 5 comments
38 points by surprisetalk | 51 comments
6 points by surprisetalk | 1 comments
634 points by beardyw | 174 comments
A Futility Closet blog post showing a diagrammatic visual proof that a² − b² = (a + b)(a − b), with a Sophie Germain quote.