Liu Hui
![](https://upload.wikimedia.org/wikipedia/commons/1/10/Liu_hui.jpg)
His major contributions as recorded in his commentary on ''The Nine Chapters on the Mathematical Art'' include a proof of the Pythagorean theorem, theorems in solid geometry, an improvement on Archimedes's approximation of , and a systematic method of solving linear equations in several unknowns. In his other work, ''Haidao Suanjing (The Sea Island Mathematical Manual)'', he wrote about geometrical problems and their application to surveying. He probably visited Luoyang, where he measured the sun's shadow. Provided by Wikipedia