Pi, a mathematical constant denoted by the Greek letter π, is the ratio of a circle's circumference C to its diameter d: π = ...

In 2009, the U.S. House of Representatives passed a resolution recognizing March 14 as National Pi Day. According to the Exploratorium, mathematicians began using π, the Greek letter pi ...

To approximate circles, the mathematician Archimedes used polygons with many sides and determined that Pi was approximately 22/7. In 1706, the Greek symbol π was first used by William Jones.

To pitch a ‘My Turn’ guest column, email [email protected]. The number conventionally represented by the Greek letter pi is truly marvelous. It can be defined as the ratio of a circle ...

RALEIGH, N.C. (WTVD) -- March 14 is National Pi Day, celebrating the mathematical constant 3.14 represented by the Greek letter pi. It's the ratio of a circle's circumference to its diameter.