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.

Nov 17, 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 repeat, and an …

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 often written …

May 17, 1999 · Succinctly, pi—which is written as the Greek letter for p, or π—is the ratio of the circumference of any circle to the diameter of that circle. Regardless of the circle's size, this ratio will...

In this post, you will learn what pi is, how to use it, its surprising properties, unexpected places it appears, and why it fascinates mathematicians and curious minds worldwide.

Sep 21, 2023 · Pi is a circle's circumference divided by its diameter. (The diameter is twice the radius or double the length from any point on the circle to its center. The circumference is the distance around …

Briefly: for the unit circle, a distance of 1pi represents only half the distance around the circle; you need a distance of 2pi to go fully around the circle.

Mar 14, 2017 · Pi - which is written as the Greek letter for p, or - is the ratio of the circumference of any circle to the diameter of that circle. Regardless of the circle's size, this ratio will always equal pi.

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.

π π is the ratio between a circle's circumference and diameter. That is, circumference diameter = π diametercircumference = π. π π is a fundamental constant in mathematics, especially in geometry, …