Originally defined as the ratio between the circumference of a circle and its diameter, pi — written as the Greek letter π — ...

SAN FRANCISCO -- Every March 14, mathematicians, scientists and math lovers around the world celebrate Pi Day, a commemoration of the mathematical sign Pi. That's because the date written numerically ...

Hey, it's Pi Day! That's right, March 14 every year is celebrated by folks everywhere because it's 3/14 or, like the first three digits of Pi, 3.14. So we all joke around with Pi pies and pizza pie ...