Need the Area of a Triangle? The Pope Can Help!

Note for Instructors

While we hope that all readers of Convergence will enjoy this article, it is meant especially to be accessible and instructive to students of geometry—in a high school class or a university course for pre-service teachers, for instance. It could also be used in a history of mathematics course, especially one for pre- or in-service teachers. Students can read it, either alone or in small groups, working the exercises as they go along.

Figure 1. The letter by Gerbert d’Aurillac to Adalbold, who later became Bishop of Utrecht, that is discussed in this article.
12th-century Austrian manuscript owned by the University of Pennsylvania Libraries.