Thank the Babylonians, not Pythagoras, for trigonometry

Most every kid learns a² + b² = c² in math. Pythagoras, right? Wrong. Babylonians used trigonometry 1,000 years before the Greeks. Time to rewrite history?

This unassuming clay tablet may yet turn the history of mathematics on its head.

It was first unearthed in 1894 near where the Iraqi capital, Baghdad, is located today. But it was left to rest, forgotten in some corner of Istanbul's

Archaeological Museum.

That was until Australian mathematician Daniel Mansfield spotted it in a photo in 2018.

Mansfield, a senior lecturer at the University of New South Wales (UNSW) in Sydney, Australia, got excited about the perfect angles he could see on it. So, he went to Turkey to investigate and find out more.

Three years later, Mansfield says he's solved the riddle of this ancient tablet.

Dating back to the Old Babylonian period about 3,700 years ago, it could be the oldest known example of applied geometry. It also holds the secrets of an ancient understanding of triangles ... and how they resolved land disputes.

Did Pythagoras copy the Babylonians?

Mansfield has published details of his find, "Plimpton 322: A Study of Rectangles," in the journal Foundations of Science.

It's a find, he says, that promises to rewrite the math history books.

"The discovery and analysis of the tablet have important implications for the history of mathematics," says Mansfield.

Until now we've gone with the story that trigonometry was invented by the ancient Greeks and more specifically by the philosopher and mathematician Pythagoras.

But Mansfield's study suggests that trigonometry was in use a thousand years before Pythagoras was even born.

Fractions, integers and angles

Mansfield is no stranger to this kind of investigative work. In fact, part of this new discovery started in 2017 when he looked at another clay tablet.

It was only about the size of a postcard and called Plimpton 322. Hence, the title of the study he's just published.

He said then that tablet was the oldest known example of