A4 Paper

I mentioned the A4 paper size (European standard) today in some of my classes and its special $\sqrt{2}$ ratio. It has the amazing property that if you cut it in half “hamburger” style it retains the ratio. Incredible, right? Beautiful, right? Nothing special about our 8.5″ x 11″ paper, that’s for sure. For extra bonus points, give a proof of this property (it’s two or three statements–short and simple).

Elegantly, A0 paper is proportioned so that it has exactly 1 square meter of area. A1 is half that size, A2 half again, and so on. For more info about A4 paper, and diagrams, visit the Wikipedia page.

2. Nice! I knew I could count on you, Drew :-). Now you just need to learn how to tag with $LaTeX$ so it looks pretty, like this: $x=y\sqrt{2}$.