The most famous original document of Babylonian mathematics is Plimpton 322. It is a partly broken clay tablet, approximately 13cm wide, 9cm tall, and 2cm thick. It was found in southern Iraq and now can be found in a collection at Columbia University, donated there by George A. Plimpton. It is believed to list 15 Pythagorean triples.

A Pythagorean triple are the three integers (a, b, c,) when a²+b²=c². The triple (6, 8, 10) is also a Pythagorean triple because some are scalar multiples of other triples: (6, 8, 10) is twice (3, 4, 5). Geometrically, if one Pythagorean triple is a multiple of another, then the corresponding triangles are similar. A triple is called primitive when there is no common factor for the three integers.

There is a method for finding infinitely many primative Pythagorean triples. Pick any r and s that satisfies the conditions on the left. Then plug them into a, b, and c.

For example, pick r = 8, s = 5. Then a = 64-25, b = 2(8)(5), and c = 64+25. So a = 39, b = 80, and c = 89 and 39² + 80² = 89²