Babylonians noticed a direct correlation between the perimeter of a circle and its diameter, where the perimeter was 3 times as large as the diameter. Archimedes wanted to measure the perimeter of a circle in an exact fashion, so he equated a circle to a number of polygons that could be divided into identical isosceles triangles. He found that any circle's perimeter divided by its diameter resulted in the same number, called Archimedes Constant, which later became known as pi (π). Archimedes knew how to calculate the area of an isosceles triangle using Pythagoras theorem, which he used to calculate the circle's area and its relationship to π. in 1450, Al Kashi calculated π more precisely by using a polygon with 3x2^28 sides to find the value of π to 14 decimal places. In 2019, Emma Haruka Iwao calculated π to more than 31 trillion decimal places. The more decimal places we calculate in π, the more accurate calculations will be.