March 14 is Pi Day, an annual celebration of the mathematical constant of pi, representing the ratio of a circle's circumference to its diameter. The holiday is observed on March 14 or 3/14 because 3.14 are the first three digits of the infinite number pi — 3.14159 ... and on and on.

Not everybody agrees pi deserves its praise. But that doesn't mean it's not without its charm. What is pi? Pi (π) is a constant describing the ratio between a circle's circumfere

Years ago, the infinite decimal 3.14 or its Greek symbol pi was mostly known to math and science geeks, but now March 14 is also a day for tasty deals. Here’s a little history to whet the appetite. The first “Pi Day” celebration was held in San Francisco in 1988 when a physicist at the Exploratorium,