Actual source: [Mansfield, D. F. (2020). Perpendicular Lines and Diagonal Triples in Old Babylonian Surveying. Journal of Cuneiform Studies, 72, 87–99. doi:10.1

Actual source: [Mansfield, D. F. (2020). Perpendicular Lines and Diagonal Triples in Old Babylonian Surveying. Journal of Cuneiform Studies, 72, 87–99. doi:10.1086/709309](https://sci-hub.se/http://dx.doi.org/10.1086/709309 https://sci-hub.se/http://dx.doi.org/10.1086/709309). The "Si." is short for [Sippar](https://en.wikipedia.org/wiki/Sippar https://en.wikipedia.org/wiki/Sippar). From a quick skim, this seems to indeed bolster Wildberger's theory about the Babylonians' use of Pythagorean triples (actually the theory predates Wildberger, but he is its main proponent). This theory claims that the triples were used as a proto-trigonometric table, a ready-made set of rational-sided right-angled triangles, as irrationals were not expressible in Babylonian numerals. (Of course, Wildberger draws motivation for his "rational trigonometry" from this, although it is a mathematical theory that needs no historic motivation.) In contrast, the more mainstream theory is that the Pythagorean triples were a product of "scribal training" or mathematical puzzle-solving (like the Japanese sangakus). This mainstream theory, despite sounding like a cop-out, still has a lot speaking for it (see [Eleanor Robson, Neither Sherlock Holmes nor Babylon: a reassessment of Plimpton 322, Historia Mathematica, Volume 28, Issue 3, August 2001, Pages 167-206](https://ora.ox.ac.uk/objects/uuid:e3d8eedb-e745-45b3-8612-71f8951599aa https://ora.ox.ac.uk/objects/uuid:e3d8eedb-e745-45b3-8612-71...), particularly pp. 183--185, for some rather convincing context). But the two can in fact be combined: who said puzzles cannot be built out of applied problems? (Many a math contest problem arose this way.)