Abu Sahl al-Quhi

Abu Sahl al-Quhi, born in the year nine hundred and forty, was a distinguished Persian mathematician, physicist, and astronomer. Originating from Kuh, an area in Tabaristan near Amol, he flourished in Baghdad during the tenth century, where he became renowned for his contributions to geometry and astronomy.

As the leader of the astronomers at the observatory established by the Buwayhid amir Sharaf al-Dawla in Baghdad in nine hundred and eighty-eight, al-Qūhī made significant strides in the field. He authored a treatise on the astrolabe, tackling complex geometric problems and showcasing his expertise in mathematics.

Al-Qūhī's mathematical pursuits included addressing Archimedean and Apollonian problems that led to equations of higher degrees. Notably, he solved the challenge of inscribing an equilateral pentagon within a square, resulting in a fourth-degree equation. His innovative work also included a treatise on the