During the third/ninth century, several commentators on Euclid’s Elements composed blocks of propositions (called ziyadat) in which they expanded specific concepts or techniques beyond the basic discussions of Euclid. Among the earliest of these ziy?d?t were three propositions created by al-‘Abbas b. Sa‘?d al-Jawhar? in an attempt to demonstrate the validity of Euclid’s definitions V, 5 and V, 7. A unique manuscript of a Persian translation of these propositions has recently been discovered. In this paper, I introduce this Persian text, offer an English translation, and discuss the relationship between the Persian and Arabic versions.
)