Pi Day is celebrated by math enthusiasts around the world on March 14. Pi = 3.1415926535. Pi, Greek letter (π), is the symbol for the ratio of the circumference of a circle to its diameter. March 14 is also the birthday of Albert Einstein. Many cities and institutions of geekery, like the Maryland Science Center, hold celebrations to party down on the mathiest day of the year.

Pi is a pretty important number, so it's fitting to have a day of celebration. There are many things that could not be built without implementing the constant pi. According to the Pi Day website, in 1706 William Jones first used the symbol for Pi (π) but Leonhard Euler made the symbol popular in 1737. Pi is a very useful constant in Mathematics. It can be used in a lot of measurements most especially in the area of circles. As expressed, it starts with 3.14 and since today is March 14 (3/14), we are celebrating Pi Day.

Nowaday’s people are celebrating Pi day with eCards and Facebook.