Euclid:Proposition/X/19

Proposition

In the words of Euclid:

The rectangle contained by rational straight lines commensurable in length is rational.

(The Elements: Book $\text{X}$: Proposition $19$)

Sources

• 1926: Sir Thomas L. Heath: Euclid: The Thirteen Books of The Elements: Volume 3 (2nd ed.) ... (previous) ... (next): Book $\text{X}$. Propositions