Another Brain Teaser

Boneman was kind enough to pass along this link that got posted on one of the General Interest forums at work. It's a geometry puzzle that took me about 45 minutes to solve, showing just how rusty I am at the moment. On the bright side, though: I did solve it, and at no point did I even consider giving up! So that's encouraging. If there's enough demand, I'll post the solution later on. Or maybe it's just so straight-forward that everyone will already know how to solve it.