
Pi | Definition, Symbol, Number, & Facts | Britannica
Oct 21, 2025 · pi, in mathematics, the ratio of the circumference of a circle to its diameter. The symbol π was devised by British mathematician William Jones in 1706 to represent the ratio …
Pi - Wikipedia
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.
Pi - Math is Fun
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 …
What Is Pi (π) in Math? A Kid-Friendly Definition
Pi (π) is a special number that tells us how the distance around a circle (its circumference) compares to the distance across the circle (its diameter). No matter the size of the circle, the …
What Is Pi? Understanding the Number & Symbol - Statistics by Jim
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 - Math.net
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 …
What is Pi? - Pi Day
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. For any circle, the distance …
What is Pi (π)? Definition, Formula, and Uses Explained
Pi, represented by the Greek letter π, is the ratio of the circumference of a circle to its diameter. It is a mathematical constant with the value equal to 3.14159.
What Is Pi, and Why Is It So Important? - ExtremeTech
Jan 25, 2025 · Pi, a mathematical constant denoted by the Greek letter π, is the ratio of a circle's circumference C to its diameter d: π = C/d.
PI - Math.com
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 …