Coba jelasin Nasir al-Din al-Tusi dari Matematik pada zaman pertengahan Islam dalam bahasa melayu dong

Spherical trigonometry was largely developed by Muslims, and systematized (along with plane trigonometry) by Persian Shi'a mathematician Nasir al-Din al-Tusi (1201–1274). He also wrote influential work on Euclid's parallel postulate.

Nasir al-Din al-Tusi, like many other Muslim mathematicians, based his theoretical astronomy on Ptolemy's work, but al-Tusi made the most significant development in the Ptolemaic planetary system until the development of the Nicolaus Copernicus. One of these developments is the Tusi-couple, which was later used in the Copernican model.