For centuries, ancient scholars and scientists have puzzled over this mysterious number. What is it, what are its uses, and how has it figured in history?

Defining Pi

www.mathselab.com

This mysterious 3.141592..., which comes in at every door and window, and down every chimney, calling itself the circumference to a unit of diameter.-Augustus De Morgan

Defining Pi

www.mathselab.com

- Denoted by the symbol π. - Defined as the ratio of the circumference of a circle to its diameter. - Referred to as Archimedes' constant - Commonly expressed as 3.1415929 or 22/7, although it is an irrational number with an infinite number of digits.

Uses of Pi

www.mathselab.com

- Used to calculate volume, surface area, as well as the circumference of three-dimensional shapes.- Here are two important formulas that use pi:Circumference = π × Diameter Area = πr2 square

Calculating Pi

www.mathselab.com

- With the advent of mathematical innovations analyses came faster and more accurate ways of calculating for pi.- In the late 16OOs, Sir Isaac Newton was able to calculate its value up to 16 decimal places with the use of his binomial theorem.

Calculating Pi

www.mathselab.com

By the advent of the 21st century, computers were able to express pi to 31,415,926,535,897 decimal places!

Pi's Relevance

www.mathselab.com

- Pi continues to puzzle and amaze people in modern society. - Piphilology is the use of different techniques to memorize as many digits of π.- It is celebrated all over the world on March 14 and is known as Pi Day.