Mathematician:Liu Hui

Mathematician
Chinese mathematician and writer.

Edited and published a book with solutions to mathematical problems presented in ("Nine Chapters on the Mathematical Art"), in which he gave:
 * a calculation of $\pi$ (pi) correct to $4$ decimal places
 * proof of the formulae for the volume of the square pyramid and tetrahedron.

Possibly the first mathematician to discover, understand and use negative numbers.

Nationality
Chinese

History

 * Born: about 220 or 225 in Wei, China
 * Died: about 280 or 295 in China

Theorems and Definitions

 * Chinese Remainder Theorem

Writings

 * 263: Commentary on the ("Nine Chapters on the Mathematical Art")
 * 263: Haidao Suanjing ("The Sea Island Mathematical Manual")