The hunt for pi began in Egypt and in Babylon about two thousand years before Christ. The Egyptians obtained the value (4/3) 4 and the Babylonians the value 3 1/8 for pi. About the same time, the Indians used the square root of 10 for pi. These approximations to pi had an error only as from the second decimal place.
Who Discovered Pi?
Archimedes was the first to theoretically approximate pi
He calculated that pi was “trapped” between 223 / 71 and 22 / 7 , or roughly 3.1428
Today we use better approximations, most of which are derived by computers
Hi, I’m Archimedes… Pi = Between 223/71 and 22/7
The Death of Archimedes
Archimedes was born in 287 BC in a Greek state called Syracuse, Sicily.
The city of Syracuse was taken over by the Romans and Archimedes was killed.
It is said that he was busy drawing circles in the dust and writing mathematical equations at the time of his death
THAT’S HOW IMPORTANT PI WAS TO ARCHIMEDES!!!!!
Currently the value of pi is known to 6.4 billion places ! 3.14128… 22/7 250 BC Archimedes Equivalence Discovery When? Who? 3.1415926535… Pi Today Computers 3.16227766... square root of 10 2000 BC Indians 3.125 3 1/8 2000 BC Babylonians 3.160493827... (4/3) 4 2000 BC Egyptians THE DISCOVERY OF PI
The Usefulness of Pi
Pi is extremely useful in calculating the area and circumference of a sphere: A = πr 2 and C = 2πr.
Many disciplines of science use π in their equations to describe the world
In fact DNA, rainbows, the human eye, music, color, and ripples all have some natural roots in pi.
Let's review some DEFINITIONS
Diameter and Radius
The distance across a circle through its center is called its diameter, D .
The radius, R of a circle is the distance from the center of a circle to a point on the edge of the circle.
So a circle's diameter is twice as long as its radius: D = 2 × R .
diameter, D radius, R
C i r c u m f e r e n c e
The distance around a circle is its circumference
π = Pi = circumference divided by diameter Every time you use these formulas, you will come up with 3.14159265… π = circumference diameter circumference 2 x radius
The space inside a circle is called the Area
I drew polygons of more than 90 sides! Take it from me… the area of a circle is π r 2
APPROXIMATELY The symbol means When speaking of pi we always use Example: π 3.14 ~ = ~ = ~ =
LET’S REVIEW THE FORMULAS! π = circumference diameter
SOME NAMES FOR PI 3.14 22 7 ___ pi π Hope you enjoyed learning about Pi!!! ~ = ~ =