Pi represents the relationship between a circle’s diameter (its width) and its circumference (the distance around the circle).
Pi Day and Pi Approximation Day are two holidays held to celebrate the mathematical constant π (pi) (in the mm.dd date notation: 3.14); since 3, 1 and 4 are the first three digits of π. March 14 is also the birthday of Albert Einstein and the two events are sometimes celebrated together.
