Liu Hui

Liu Hui was a Chinese mathematician of the third century CE who lived in the state of Cao Wei during the Three Kingdoms period and, in 263 CE, published a commentary on the Jiu Zhang Suan Shu, known in English as The Nine Chapters on the Mathematical Art. His commentary is the source of several results that matter to the history of computation. It contains a method for approximating pi by inscribing polygons in a circle, first with 192 sides and then with 3072 sides, which gave 3.14159, and a systematic method for solving linear equations in several unknowns that is described as Gaussian elimination. He also gave a proof of a theorem identical to the Pythagorean theorem and worked on the volumes of solid figures. His separate work Haidao Suanjing, The Sea Island Mathematical Manual, applied geometry to surveying. Because the pi method and the elimination procedure are explicit step by step procedures, he appears in this atlas as an early author of algorithms.