What is the Pythagorean Theorem? It is the theorem to find the third side length of only a RIGHT triangle when knowing only two sides. The side length across from the right angle is called the hypotenuse. The other two sides are called the legs. When you square the legs and then add them together you get the square area of the hypotenuse.
In history Pythagoras was said to have created the Pythagorean Theorem. Pythagoras was born in 500 BC on the island Samos and was a Greek philosopher. Pythagoras did not write the Pythagorean Theorem, but proved it to be true. The Babylonians and the Indians wrote the theorem. In fact Pythagoras may not have worked on the proof at all. Pythagoras was a teacher whose students may have worked on the proof and then gave credit to it to Pythagoras. That is just the way his school went.
