# Liu Hui

Liu Hui (Chinese刘徽; * 220, † 280 ) was a Chinese mathematician. He lived in the Wei kingdom.

Liu Hui is known for his comments on the Jiuzhang SuanShu, the "nine books of arithmetic technique." This is a collection for the solution of mathematical problems from everyday life area. Liu Hui published the Jiuzhang SuanShu in the year 263 with his own comments, which is also the oldest surviving issue. Among his outstanding work

- The calculation of Pi by enrolling regular polygons in the circle. He hit 3.14 before a good approximation.
- The solution of linear systems by means of a method which later became known as Gaussian elimination method.
- The calculation of the volume of prism, pyramid, tetrahedron, cylinder, cone and truncated cone.

He also wrote the Haidao suanjing ( " Mathematical Handbook of Sea Isle " ), one of the ten classic ( Suanjing shi shu ) of the medieval Chinese mathematics. It was written 263 and contains methods for surveying, which were used in the next thousand years in East Asia to this book.