Pythagoreans noticed that strings produce different notes when they vibrate. If the ratios of the length of two strings are whole numbers, the notes make different pitches. They also knew that any triangle with side ratios of 3:4:5 was a right triangle. The Pythagoreans were the first to prove that the Pythagorean Theorem was correct, even though Pythagoras learned it from the Babylonians in his travels. During the 6th century BC, a square with a side of n was shown as the area of a square with a side of n. The Pythagorean Theorem stated that in a right triangle, the square of side a added to the square of side b will be equal to the square of side c (the hypotenuse).

Irrational Numbers

Irrational numbers are numbers with decimals that do not terminate, or repeat. The most widely known irrational number is p (pi). Pi can be calculated to billions of digits that go on forever. The number pi is related to curves, ellipses (ovals) and circles.