The famous mathematician whose full name is Abu Nasr Mansur ibn Ali ibn Iraq is more familiarly called Abu Nasr Mansur. He was known to be born in 960 AD in Gilan, Persia and died in 1036 AD in Ghazni, (now in Afghanistan). Abu Nasr Mansur is a Muslim mathematician from Persia. He is known as the discoverer of the law of sin. Abu Nasr Mansur has made important contributions in the world of science. Some of Abu Nasr’s works are indeed focused on mathematics, but some of his writings also address the problem of astronomy.

In the field of mathematics, he has so many works that are very important in trigonometry. Abu Nasr also succeeded in developing the work of a Roman mathematician, astronomer, geographer and ascrologist named Claudius Ptolemy (90 BC-168 BC).

In addition, he also studied, criticized, and developed theories, as well as laws that had been developed by a Greek mathematician and astronomer, Menelaus of Alexandria (70 BC – 140 BC). One of the works of the Muslim scientist is his commentary in The Spherics of Menelaus. His collaboration with al-Biruni also succeeded in spawning around 25 major works, around 17 of his works still survive today.

In the field of mathematics, Abu Nasr has seven works, while the rest of his works are in the field of astronomy. All of his surviving works have been translated and published in European languages. In particular Abu Nasr presented as many as 20 of his work to the student, Al-Biruni.

His role was very large in the development of the science of trigonometry which he developed from Ptolemy’s calculations which are still used today. In addition, he also contributed greatly in developing and compiling tables that can help astronomical observations.

His other achievement was to develop The Spherics of Menelaus, an important text on Greek astronomy, since Menelaus’s original work was destroyed. His work is arranged in three books. The first book studies the content / wealth of triangular shapes, the second book examines the content of parallel systems in a ball / shape that intersects large circles, the third book provides evidence of Menelaus’ proposition. In his trigonometric work, Abu Nasr Mansur discovered the sine law as follows:

a / sin A = b / sin B = c / sin C.

The history of science notes, the scientist who lived in the era of the Samaniyah Dynasty was also one of the originators of the experimental scientific method. He not only mastered various sciences such as physics, anthropology, psychology, chemistry, astrology, history, geography, geodesy, mathematics, pharmacy, medicine, and philosophy, but he also contributed greatly to each field of science he mastered. Abu Nasr Mansur spent the rest of his life in the palace of Mahmud in Ghazni in the eleventh century. However, his work and contribution to the development of world science will remain remembered for all time.