# Abu Nasr Mansur

**Abu Nasr Mansur ibn Ali** (c. 970 - 1036) was a Khwarazmian mathematician. He is well known for discovering the sine law.

Abu Nasr Mansur was born in Khwarazm to a ruling family of the region. He was thus a prince within the political sphere. He was a teacher of Al-Biruni and also an important colleague of the mathematician. Together they were responsible for great discoveries in mathematics and dedicated many works to one another.

Most of Abu Nasr's work focused on math, but some of his writings were on astronomy. In mathematics, he had many important writings on trigonometry, which were developed from the writings of Ptolemy. He also preserved the writings of Menelaus of Alexandria and reworked many of the Greeks theorems.

He died in modern-day Afghanistan near the city of Ghazna.