There's a delightful mathematical moment in the movie Merry Andrew, when Danny Kaye, playing schoolmaster Andrew Larabee, breaks into song to teach the Pythagorean theorem.
I was reminded of this scene by a sentence in an article about the Pythagorean theorem in the October issue of Mathematics Magazine. The Pythagorean theorem "is probably the only nontrivial theorem in mathematics that most people know by heart," comments Darko Veljan of the University of Zagreb in Croatia.
Indeed, if there is one thing that someone might remember from grade school mathematics, it's the fact that "the square of the hypotenuse of a right triangle is equal to the sum of the squares of the two adjacent sides."
According to one legend, Pythagoras (c.580