My paper will explore an example of an institution of higher education in the medieval Islamic world, the knowledge that was imparted there and its practical application. I will use both written sources and material culture remains uncovered during building restoration work in the city of Zabid, Yemen. Zabid was founded in 820. It soon started to grow into a major economic and cultural centre. In 1173 the Ayyubids conquered Yemen and introduced the madrasa as an institution of higher education. About two hundred years later, in 1393, a survey of Zabid’s religious buildings was ordered by the then ruling sultan of the Rasulid dynasty (1229-1454); it recorded some 230 mosques and madrasas, a figure that reflects the city’s importance as a centre of learning. Zabid attracted students and scholars from all over the Islamic world. From the historical sources we learn that Zabid acquired a reputation for teaching and scholarship not only in the religious sciences but also in the mathematical sciences including arithmetic, algebra, astronomy and surveying. Tangible evidence of good command of the mathematical disciplines was found during building restoration work in the Iskandariyya madrasa in Zabid in the sophisticated geometric designs of the painted dome decorations. Two-dimensional designs had to be fitted to curved surfaces, which involved calculated distortions of distances, angles and shapes. Equally important was the practical application by the artisan. As a result, the geometric designs can be read correctly from the ground as if they had been drawn on a flat surface.