Origins: 3.14159265…

How do you find the holy grail of mathematics? You start with a circle, which is the easiest geometric shape to draw (just fix one end of a string in place and swing the other end around it, inscribing a circle). Then measure the circle’s perimeter (also known as the circumference) and the distance across its widest point (the diameter). Divide the circumference by the diameter—and you have that well-known but eternally daunting number, p, or pi, which has a value of 3.14159265… That is part of the mystique of p: Whatever the size of the circle, the value […]