The number represented by pi (π) is used in calculations whenever something round (or nearly so) is involved, such as for circles, spheres, cylinders, cones and ellipses. Its value is necessary to ...

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

Pi Approximation Day, also known as Casual Pi Day, is celebrated annually on July 22nd. The day recognises and appreciates the mathematical consonant of pi (π), which is known in various aspects of ...