Why is [math]\pi[/math] what it is?

Ancient civilizations needed the value of π to be computed accurately for practical reasons. It was calculated to seven digits, using geometrical techniques, in Chinese mathematics and to about five in Indian mathematics in the 5th century AD. read more

Pi is a theoretical construct, not a physical one. The assumptions pi makes to come into being is generally valid only in flat spaced Euclidean geometry. Pi does not exist outside such a universe. read more

In the Palais de la Découverte (a science museum in Paris) there is a circular room known as the pi room. On its wall are inscribed 707 digits of π. The digits are large wooden characters attached to the dome-like ceiling. read more

Pi (π) is the ratio of the circumference of a circle to its diameter. It doesn't matter how big or small the circle is - the ratio stays the same. Properties like this that stay the same when you change other attributes are called constants. read more