*Sine, cosine, cosine, sine, 3.14159! Go, Pi Day!* In celebration of Pi Day every year (March 14th, or 3/14), MSA serves slices of pie to every student at lunch. Besides the promise of free food, what is the celebration of pi day all about?

First off, we’ll start with a definition of pi. Unlike the edible pastry filled with anything from berries to chocolate, pi (spelled without the *e*) is represented by the mathematical symbol π and is the ratio of the circumference (the distance around a circle) of a circle to its diameter (the distance across a circle). The ratio holds true for all circles, no matter what circumference or diameter they have. This irrational number has an infinite amount of digits beyond the decimal point, starting with 3.14159265358979.

Archimedes, a Greek mathematician, was one of the first people to approximate pi by using multiple-sided polygons. Although his estimate of pi was a little large at 22/7, subsequent mathematicians and scholars were able to eventually approximate pi more closely, up to trillions of digits after the decimal place! Not until 1737 was the symbol for pi actually developed by Leonhard Euler, a Swiss mathematician. In math, especially with geometry, pi is very important. It is necessary to find the area of a circle (by the equation A=πr^{2}), the volume of a cylinder (with the equation V=πr^{2}h), and many other computations where r represents the radius (half the diameter).

Now that you (hopefully) have a better idea of what pi is, you can appreciate it as you are eating your pie next week!