Pythagoras of Samos (570BC-495BC) was a Greek philosopher whose teachings and philosophy not only influenced other Greek philosophers such as Plato (424BC-347BC), but also Western scientists such as Johannes Kepler (AD 1571-AD 1630) and Isaac Newton (AD 1642-AD 1727).

He is most famous today for the theorem bearing his name, Pythagoras’ theorem. It states that, in a right-angled triangle, the square of the longest side is equal to the sum of the squares of the other two sides. But did Pythagoras actually discover this theorem himself?

Many historians argue that Pythagoras did not discover the theorem himself, but add that, perhaps, he was the one who introduced it to the Greeks, after learning it from either Babylonian or Indian mathematics. Both the Babylonians and the Indians knew of Pythagoras’ theorem centuries before the Greeks.

But did Pythagoras, at least, provide the first proof of the theorem?

According to Walter Burkert, professor emeritus of classics, the answer is probably no, noting that no proof was ever attributed to Pythagoras. Moreover, Danish historian Jens Høyrup remarks that the Babylonians not only knew of Pythagorean triples (three numbers a,b,c satisfying a²+b²=c²) but also how to apply them. This seems to suggest that they may have had a proof of Pythagoras’ theorem available.

Whatever happened, it is certain that Pythagoras’  theorem is a hugely important result in geometry.