This is the opening page of the section of the geometrical work of Oronce Fine (1494-1555) dealing with Euclid's work on circles. This is part of Fine's major work entitled *Protomathesis* (1530), which covered arithmetic, astronomy and astronomical instruments, as well as geometry. The pages displayed give a somewhat theoretical treatment of geometry, but Fine then goes on to practical matters dealing with measuring length, height, surface area, and volume.