# Pythagorean Theorem!

## History

A long long time ago, not in a galaxy far away, in ancient Greece, a mathematician named Pythagoras lived. Pythagoras lived from about 569-500 B.C.E. In his lifetime, he created a group of followers called the Brotherhood of Pythagoras. They were devoted to studying mathematics. Pythagoras and his group of followers believed that "Numbers ruled the universe." One of the mathematical ideas Pythagoras came up with is the Pythagorean theorem. He noticed that there was a special relationship between the sides of a right triangle and came up with a formula to describe that relationship.

## The theorem.

The Pythagorean theorem states that the sum of the squares of the legs of a right triangle is equal to the square of the hypotenuse. In other words, for a right triangle with legs a,b and hypotenuse c,
Pythagoras in 2 minutes 2

## Common Questions

How can I prove the Pythagorean theorem?

There are MANY ways to prove this theorem. Here is a website that shows the various ways to prove this fundamental theorem.

http://www.cut-the-knot.org/pythagoras/index.shtml

What if I'm only given one side of the triangle?

Unless you have a special triangle (30-60-90 or isosceles) you will not be able to use the Pythagorean theorem.

Can I use this for all triangles?

No. Only right triangles.

## Now put it all together!

Colin Dodds - Pythagorean Theorem (Math Song)