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Mathematical Treasures - Qāḍī Zāda al-Rūmī's Geometry

Frank J. Swetz and Victor J. Katz


This is page 14 from the Geometry (1412) of Qāḍī Zāda al-Rūmī (1364-1436). Al-Rūmī's book was a commentary on the Fundamental Theorems, written by al-Samarqandī (1250-1310) and containing a discussion of 35 of Euclid's propositions. The book shown in the image is a later copy of al-Rūmī's work, probably written in the sixteenth century. At the top of the page is a discussion of Euclid's Proposition I-5, the "Bridge of Asses" proposition that the base angles of an isosceles triangle are equal. At the bottom, there is a discussion of I-6, the converse of I-5. Al-Rūmī was an astronomer and mathematician in the court of Ulugh Beg (1393-1449) in Samarkand. He and his colleagues compiled the first complete star catalogue since the time of Ptolemy.

Frank J. Swetz and Victor J. Katz, "Mathematical Treasures - Qāḍī Zāda al-Rūmī's Geometry," Convergence (January 2011)


Mathematical Treasures from the Smith and Plimpton Collections at Columbia University