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Science

Plimpton 322

A Babylonian tablet lists Pythagorean triples a thousand years before Pythagoras.

When
Known to
± 100 years
Era
Bronze Age, Holocene

The tablet, from around 1800 BCE, tabulates numbers that form right triangles with integer sides. Whether it is a trigonometric table, a teacher's list of problems with clean answers, or something else is argued, but its content is not in doubt: Old Babylonian scribes knew the relationship between the sides of a right triangle and could generate examples systematically. Mesopotamian mathematics also solved quadratics and approximated square roots to several places.

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