The number π (/ paɪ / ⓘ; spelled out as pi) is a mathematical constant, approximately equal to 3.14159, that is the ratio of a circle 's circumference to its diameter.

Dec 10, 2025 · Pi, in mathematics, is the ratio of the circumference of a circle to its diameter. Because pi is irrational (not equal to the ratio of any two whole numbers), its digits do not …

Draw a circle with a diameter (all the way across the circle) of 1. Then the circumference (all the way around the circle) is 3.14159265... a number known as Pi. Pi (pronounced like "pie") is …

Pi is a constant value. That is, the ratio of the circumference to the diameter is the same for all circles. The drawing below shows the circumference of a circle that has been "straightened …

Pi \ (\pi\) is the ratio between a circle's circumference and diameter. That is, \ [\dfrac {\text {circumference}} {\text {diameter}}=\pi.\] \ (\pi\) is a fundamental constant in mathematics, …

What is pi in math terms? In math, pi is the ratio of a circle’s circumference to its diameter. π is an irrational, infinite decimal often written as 3.14159.

Pi is a name given to the ratio of the circumference of a circle to the diameter. That means, for any circle, you can divide the circumference (the distance around the circle) by the diameter …

Pi (often represented by the lower-case Greek letter π), one of the most well-known mathematical constants, is the ratio of a circle’s circumference to its diameter.

The 1998 film Pi is a dark, strange, and hyperkinetic movie about a mathematician who is slowly going insane searching for a pattern to the Stock Market. Both a Hasidic cabalistic sect and a …

Discover what pi (π) is and why it matters in math. Learn how it's used to calculate circumference, area, radians, and more. Simple explanations with examples.