1: Pythagoras has long been considered the man that discovered the pythagorean theorem. There is more to this man however.
3: a^2+b^2=c^2 This is one of the most recognizable theorems we know today. There are many proofs and uses for this equation.
4: Pythagoras had his school and his followers. We may never know who exactly discovered the theorem. Pythagoras or his students. Still, he has a place in mathematic history.