Pi Day is on March 14. Pi, also known by the Greek letter “π,” is a constant value used in math that represents the ratio of a circumference of a circle to its diameter, which is just about 3.14….15…9265359… (and so on). Not only that, but the fourteenth of March is also Albert Einstein’s birthday, so all together it’s nothing short of a mathematician’s dream day. HISTORY OF PI DAY To learn about pi, we need to go back a few thousand years and learn about this elusive number. The value of pi was