ABSTRACT
This paper traces the study of geometry in various cities of the Arab world in the fifteenth and the seventeenth centuries. The comparison of the information provided by two writers of scholarly biographies is chosen as a tool for discussing the conditions and trends that a particular mathematical discipline experienced within a relatively clear delineated geographical and cultural area. One major point of the discussion is the contradiction between the themes of the extant mathematical manuscripts of the two periods and the information provided by the dictionaries. This contradiction poses a challenge to the standard tools we use for reconstructing the history of the mathematical sciences in post-classical Islamic societies.
