Since 2018, an Australian mathematician at the University of New South Wales, Dr. Daniel Mansfield, has been studying a clay tablet known as Si.427 which was discovered in what is modern day central Iraq in the late 19th century, and his recently published findings are completely re-writing mathematics history as we know it.
This artifact had been on display in a museum in Istanbul for over a century without anyone realizing the signifigance of it's engravings. Dr. Mansfield, who had already been studying related artifacts from the Old Babylonian (OB) period (1900 - 1600 BCE) since 2017, was able to connect Si.247 to another OB artifact known as Plimpton 322. On both of these artifacts, Mansfield was able to decipher that ancient Babylonians had developed a very basic version of modern day Trigonometry, the study of triangles. This is evident in the presence of numerous triangles composed of what we now call "Pythagorean Triples" - quite the feat given that Pythagoras wouldn't be born for another thousand years.
While the Ancient Greeks developed their trigonometry by studying the night sky, Ancient Babylonians developed these special triangles to aid in land surveying. The concept of "owning" land was relatively new, and it was necessary to devise a way to lay exact boundary lines between neighboring land owners. By using Pythagorean triples to form perfect right triangles, Ancient Babylonian land surveyors could form perfect right angles and more neatly partition land!
To read more about Dr. Mansfield's findings, check out this article from Phys.org