Abu 'l-Wafa? Buzjani (d. 388/998) was a mathematician and astronomer and a native of Buzjan near Nishapur. He studied arithmetic with two of his uncles, probably in Buzjan. When he was nineteen years old he went to Baghdad. There he further developed himself to become one of the leading scientists of his age, working at the Buyid court. He was a contemporary and protector of the chronicler of intellectual and artistic life in Baghdad at the time, Abu Hayyan al-Tawhidi (d. ca. 414/1023). In the bibliographical literature more than twenty works are ascribed to him, many of which were lost. The present work was originally written in Arabic under the title Kitab fi ma yahtaj ilayhi 'l-sani? fi a?mal al-handasa. It is a groundbreaking work in that Buzjani was the first to write a monograph on practical geometry as justified by the rules of theoretical geometry. Medieval Persian and French translation, with introductions and notes.