• #### Pi - Wikipedia

https://en.wikipedia.org/wiki/Pi
The symbol used by mathematicians to represent the ratio of a circle's circumference to its diameter is the lowercase Greek letter π, sometimes spelled out as pi, and derived from the first letter of the Greek word perimetros, meaning circumference. In English, π is pronounced as "pie" (/ p aɪ / PY).
• #### What Is Pi? - Live Science

https://www.livescience.com/29197-what-is-pi.html
Oct 19, 2018 · By definition, pi is the ratio of the circumference of a circle to its diameter. In other words, pi equals the circumference divided by the diameter (π = c/d). Conversely, the circumference is equal to pi times the diameter (c = πd). No matter how large or small a circle is, pi will always work out to be the same number.
• #### PI - math

http://www.math.com/tables/constants/pi.htm
(Math | Miscellaneous | Constants | PI) 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 and always get exactly the same number. It doesn't matter how big or small the circle is, Pi remains the same.
• #### Pi | Definition of Pi by Merriam-Webster

https://www.merriam-webster.com/dictionary/pi
Definition of pi. plural pis play \ˈpīz\. 1 : the 16th letter of the Greek alphabet — see Alphabet Table. 2 a : the symbol π denoting the ratio of the circumference of a circle to its diameter. b : the ratio itself : a transcendental number having a value rounded to eight decimal places of 3.14159265.
• #### Pi

https://www.mathsisfun.com/numbers/pi.html
Pi ( π) The Circumference divided by the Diameter of a Circle. To help you remember what π is ... just draw this diagram.
• #### What is Pi? (with pictures) - wisegeek.com

https://www.wisegeek.com/what-is-pi.htm
Apr 15, 2019 · Pi is the 16th letter of the Greek alphabet, but it is best known as the symbol used to name a mathematical relationship: the ratio between the circumference of a circle and its diameter. As such, it is a mathematical constant and has many uses. Most obviously, it can be used to calculate the circumference of a circle...
• #### What Is Pi? | Wonderopolis

https://www.wonderopolis.org/wonder/what-is-pi
Have You Ever Wondered... Pi is the ratio of a circle's circumference to its diameter. Regardless of the size of the circle, pi is always the same number. So, for any circle, dividing its circumference by its diameter will give you the exact same number: 3.14159…or pi. Pi is also an irrational number,...
• #### What is Pi? (π explained) - YouTube

https://www.youtube.com/watch?v=wNcFAQHJWAU
Dec 16, 2011 · What is pi? (π explained) a brief explanation of the constant Pi Pi=3.14159265... C = circumference = perimeter D = diameter = line dividing circle in half R = radius = half the diameter ...
• #### Pi - definition of pi by The Free Dictionary

https://www.thefreedictionary.com/pi
(pī) An irrational number that has a numerical value of 3.14159265359... and is represented by the symbol π. It expresses the ratio of the circumference to the diameter of a circle and appears as a constant in many mathematical expressions.
• #### 100,000 Digits of Pi - University Of Illinois

http://www.geom.uiuc.edu/~huberty/math5337/groupe/digits.html
100,000 Digits of Pi 3.141592653589793238462643383279502884197169399375105820974944592307816406286 ...