Commentary on Proposition X.66

Back to Proposition X.66.

[Folio 0151 | p. 147]

The proofs of this and the following propositions up to X. 70 inclusive are easy and require no elucidation. They are equivalent to saying that, if in each of the preceding irrational straight lines $\frac{m}{n}\rho$ is substituted for $\rho$, the resulting irrational is of the same kind as that from which it is altered.