A greek man called Pythagoras.
Because he did not write things down, it is hard to say. Most historians believe that the Sumerians used it, but Pythagoras proved it to always be true.
It was years before, Pythagoras(580 BC - 500 BC) is said to have discovered Pythagorean Theorem. Strangely, 5 centuries after Pythagoras lived, the theorem Pythagorean was attributed to him. The discovery of the theorm Pythagorean came when Pythagoras was waiting for the tyrannical ruler, Polycrates. An interesting idea had flashed Pythagoras mind: A diagonal line can be used to cut or divide the square and two right triangles would be produced from the cut sides. After examining it further, Pythagoras formulated the idea in mind. Happy to help you.
Pythagoras is called the father of numbers because he discovered the Pythagoras theoram.
Pythagoras discovred it to find unknown sides in a right angled triangle
This result was known hundreds of years before the birth of Pythagoras.
it's when you have a right triangle and the two sides that form the right angle added together equals the the diagonal side (other side not used)
Cool question ! Answer - half it then cube it to prove it - an example for you if cube diagonal (not square diagonal) is 100, then using pythagoras theorm the square diagonal = 70.71068, If square the square diagonal = 70.71068, then using pythagoras theorm the side length = 50 therefore the volume = 50 ^ 3 = 25000 units works with any numbers
Discovered the pythagorean therom