Pi, the ratio of the circumference of a circle to its diameter, has been know to exist for thousands of years. Even before the common era, ancient mathematicians had found approximations for pi that were accurate to two digits (3.1). The Babylonians used 25/8 as an approximation of pi. The ancient Egyptians used 16/9 squared for pi. The next to improve the approximations for pi were Chinese mathematicians. The Chinese approximation was correct to...