Commentary on Proposition VI.21

Back to Proposition VI.21.

[Folio 0246 | p. 240]

It will be observed that the text above omits a step which the editions generally have before the final inference “Therefore A is similar to B.” The words omitted are “so that A is also equiangular with B and [with B] has the sides about the equal angles proportional.” Heiberg follows $P$ in leaving them out, conjecturing that they may be an addition of Theon’s.