Original: The theorems of Alhacen, Khayyam and al-Tusi on quadrilaterals, including the Ibn al-Haytham–Lambert quadrilateral and Khayyam–Saccheri quadrilateral, were the first theorems on hyperbolic geometry.
Simplified: The theorems of Alhacen, Khayyam on quadrilaterals, were the first theorems on hyperbolic geometry.