π what
What is pi?
mathematicsnumbers
Quick Answer
Pi (Ο) is the ratio of a circleβs circumference to its diameter, about 3.14159.
The Full Story
Every circle, whatever its size, has a circumference about 3.14159 times its diameter. Pi is irrational, meaning its decimals never end or repeat, and it cannot be written exactly as a fraction; 22/7 is a common approximation. Archimedes estimated it around 250 BC as between 3 1/7 and 3 10/71. The symbol Ο was popularised by Leonhard Euler in the 1700s. Computers have calculated pi to over 100 trillion digits, though NASA uses only about 15 decimal places for interplanetary navigation.
Key Facts
1.Pi is about 3.14159
2.It is irrational
3.Calculated to over 100 trillion digits
YouTube Angle
Suggested video title for this topic:
"Why NASA only needs 15 digits of an infinite number"