If you know math, you’re aware of the mathematical sign of pi. If you’re really into math, you know of Pi Day, occurring on March 14, or 3/14. Pi day this year occurred on Monday, so you may be wondering why we’re posting today as well! Well, I thought I’d give a bit more information about pi, the history of it, and the history of celebrating Pi Day.

Let’s start with a brief overview of pi. Pi is a mathematical sign representing the ratio of a circle’s circumference to its diameter, typically approximated to 3.14. Because of its connection to circles, pi is used to calculate the volumes of solids, area and perimeter of circles, and many other applications.

So how did we come up with this?

The first calculation of pi is attributed to Archimedes, who approximated the area of a circle using the Pythagorean Theorem. He found the area of two regular polygons: the one inscribed into the circle, and the one which the circle is circumscribed. This way he could find an approximation between the areas of those two polygons, and therefore an approximation of the area of the circle.

In the 1700s, the symbol for Pi was introduced and popularized. Along with that, Georges Buffon found a way to calculate Pi based on probability in the same century.

This leads to what was my biggest question: How did Pi Day come about? I know the digits of the date are significant, but why do we celebrate pi?

Pi Day was founded in 1988 by a physicist named Larry Shaw. March 14 is also Albert Einstein’s birthday, adding a bit of extra celebration to the date by physicists. The first Pi Day featured a circular parade and fruit pies. Here at Maplesoft, we celebrated with pie, and learning how to make art with Maple Learn.

Maybe someday we’ll have more days celebrating mathematical concepts, but for now, start planning for next year’s Pi Day! Perhaps you can make it bigger and better than the first celebration in 1988. I hope your Pi Day this year went well, and happy Friday!