Written in Stone: The World’s First Trigonometry Revealed in an Ancient Babylonian Tablet

The ancient Babylonians—who lived from about 4000 BCE in what is now Iraq—had a long forgotten understanding of right-angled triangles that was much simpler and more accurate than the conventional trigonometry we are taught in schools. Our new research, published in Historia Mathematica, argues that the Babylonians were able to construct a trigonometric table using only the exact ratios of sides of a right-angled triangle. This is a completely different form of trigonometry that does not need the familiar modern concept of angles (Figure 1). At school we are told that the shape of a right-angled triangle depends