If you're interested in pi, the book A History of Pi by Petr Beckman is a must read, not only for the good information but also for his nonconventional approach

If you're interested in pi, the book A History of Pi by Petr Beckman is a must read, not only for the good information but also for his nonconventional approach. Note that Archimedes used a 96-sided polygon to estimate bounds on the value of pi (http://en.wikipedia.org/wiki/Pi http://en.wikipedia.org/wiki/Pi)! This was quite a feat since arithmetic calculations and algebraic was one area that ancient Greeks were weak at.