Rashed, Roshdi Ibn Sahl et al-Qūhī: Les projections. Addenda and corrigenda to: Géometrie et dioptrique au \(X^e\) siècle. (French) Zbl 0986.01006 Arab. Sci. Philos. 10, No. 1, 79-100 (2000). The author notes a few new titles to be ascribed to lbn Sahl and gives text, translation, and commentary of two fragments of Ibn Sahl quoted by Al-Sijzī. The first shows the construction of a right triangle, given one side and the sum of the other two (by an ellipse and a circle.) The other one is the reconstruction of a sphere from its stereographic projection. In addition, there are a number of corrections and additions to the author’s book: Géométrie et dioptrique au Xème siècle (1993; Zbl 0946.01003). Reviewer: H.Guggenheimer (West Hempstead) MSC: 01A30 History of mathematics in the Golden Age of Islam Keywords:construction; stereographic projection Biographic References: Ibn Sahl; al-Qūhī Citations:Zbl 0946.01003 PDFBibTeX XMLCite \textit{R. Rashed}, Arab. Sci. Philos. 10, No. 1, 79--100 (2000; Zbl 0986.01006) Full Text: DOI