Pythagoras’ Theorem states that ‘the square on the hypotenuse is equal to the sum of the squares on the two shorter sides’. Of course, it only applies to right-angled triangles, but is a very important theorem. It can also be used in reverse, to check if an angle is 90o. See how well you remember it in this Maths GCSE quiz!
Although Pythagoras didn’t discover the relationship between the length of sides in a right-angled triangle (the Babylonians knew this 1,000 years earlier) he was possibly the first to prove it, over 2,500 years ago. Pythagoras was more than just a mathematician – he founded a school that studied philosophy and religion, and was head of the Secret Pythagorean Society.