The Spanish Muslim astronomer and mathematician, Abu Abdullah Mohammad ibn Mu'az al-Jayyani

Compiled By: Syed Ali Shahbaz
On 16th of the Islamic month of Zil-Hijjah in 471 AH, the Spanish Muslim astronomer and mathematician, Abu Abdullah Mohammad ibn Mu'az al-Jayyani, passed away at the age of over 90. He was born in Cordova and after completing his studies in Islamic Spain, he went for higher studies to Cairo and stayed in Egypt for four years, before returning to his homeland, where besides his scientific activities, he served as Qazi or Judge.
Al-Jayyani wrote important commentaries on Euclid's Elements. He also wrote the first known treatise on spherical trigonometry as a discipline independent from astronomy. His work on spherical trigonometry contains formulae for right-handed triangles, the general law of sines, and the solution of a spherical triangle by means of the polar triangle.
This treatise later had a strong influence on European mathematics, and his definition of ratios as numbers and method of solving a spherical triangle when all sides are unknown, influenced scholars of the Renaissance period.