[Folio 0105 | p. 101]

DEFINITIONS II.

1. Given a rational straight line and a binomial, divided into its terms, such that the square on the greater term is greater than the square on the lesser by the square on a straight line commensurable in length with the greater, then, if the greater term be commensurable in length with the rational straight line set out, let the whole be called a first binomial straight line;

2. but if the lesser term be commensurable in length with the rational straight line set out, let the whole be called a second binomial;

[Folio 0106 | p. 102]

3. and if neither of the terms be commensurable in length with the rational straight line set out, let the whole be called a third binomial.

4. Again, if the square on the greater term be greater than the square on the lesser by the square on a straight line incommensurable in length with the greater, then, if the greater term be commensurable in length with the rational straight line set out, let the whole be called a fourth binomial;

5. if the lesser, a fifth binomial;

6. and if neither, a sixth binomial.