Euclid:Proposition/XIII/5

From ProofWiki
Jump to navigation Jump to search

Proposition

In the words of Euclid:

If a straight line be cut in extreme and mean ratio, and there be added to it a straight line equal to the greater segment, the whole straight line has been cut in extreme and mean ratio, and the original straight line is the greater segment.

(The Elements: Book $\text{XIII}$: Proposition $5$)


Sources