This manuscript of Euclid’s Elements was produced in Germany in 1460 (Plimpton MS 157).
This page presents a discussion of triangles:
These images have been obtained through the kind cooperation of the Rare Book and Manuscript Library of the Columbia University Libraries. These and more images may be accessed via Digital Scriptorium, a digital collection of medieval and early Renaissance manuscripts made available by a consortium of cooperating university libraries headed by the University of California, Berkeley.