This episode discusses the origins of square roots and the Pythagorean theorem. In 1500 BC, Babylonians studied the square and noticed an oddity, that to create a square with 2 elements they would need 2 times 2 of them. This is why numbers multiplied by themselves are called squared numbers, because they always create a perfect square. In 500 BC, Pythagoras noticed that some numbers operated by 3 and found that triangles that fit inside rectangles could be used to illustrate the Pythagorean triplet, these were called right triangles. 200 years later, Euclid presented the Pythagorean Theorem where in a right triangle, if you add the sum of the two squares of the right angle, the sum equals the square of the opposite side. In the 9th century when algebra was invented, the Pythagorean theorem became the calculation basis for many scientific fields, and the equation  was used to find the square measure of a number in specific situations. To find the number itself, you must go back to its root, or as the Babylonians understood, finding the number for which the square is known.