March 14 is Pi Day. Today we celebrate the Greek letter and mathematical symbol pi, or π, which is an irrational and supposedly unending number. So far, π has been calculated up to 31 trillion digits. π is used in math to calculate the area and circumference of a circle. 

Around 1900-1680 BC, the prehistoric Babylonians calculated π to be three times the radius of a circle. This was wrong as π is closer to 3.14. Next, in 1650 BC left, ancient Egyptians left records of formulas that calculated π to be 3.1605, which was closer to the actual value than the Babylonian records.

The first historical record of someone calculating π correctly was Archimedes in approximately 287-212 BC. Archimedes was one of the greatest mathematicians of his time and calculated π using the Pythagorean Theorem. He used the areas of two identical trapezoids, one of which circumscribed the circle and the other was inscribed in the circle. The space between the two circles was the area of the circle and Archimedes used this to find π. While he did not find the precise value of π, Archimedes found out that π is between 3 1/7 and 3 10/71. 

Much later in the 1700s AD, mathematicians used the Greek letter π as the symbol for pi. This was first proposed by mathematician William Jones in 1706 and was later used by another mathematician Leonhard Euler in 1737. 

To find the area of a circle with π, you simply multiply π by the radius squared. When calculating the circumference of a circle, π must be multiplied by the diameter of the circle. Many people use π in their daily lives to help with these simple calculations. Americans celebrate Pi Day on the 14th of March because March is the third month so it looks like 3/14, which is the first digits of π (3.14159265358979323…). In honor of the number, we bake pies, referring to the homonymous pronunciation of pi and pie. Above is a picture of a pie that was taken by EC Author that was made to celebrate Pi Day! Hope you enjoy some delicious pies today while pondering this mysterious number that has intrigued mathematicians nturies.