Math Mondays with Steven Strogatz

Square Dancing, the latest entry in Strogatz's series on Math: From Basic to Baffling, deals with geometry:

To illustrate the pleasures of geometry, let’s revisit the Pythagorean theorem, which you probably remember as a² + b² = c². Part of the goal here is to see why it’s true and appreciate why it matters. Beyond that, by proving the theorem in two different ways, we’ll come to see how one proof can be more “elegant” than another, even though both are correct.