Page:First six books of the elements of Euclid 1847 Byrne.djvu/53

Rh F in any triangle one angle  be greater than another  the side  which is opposite to the greater angle, is greater than the side  opposite the less.

If be not greater than  then must = or <.

If =  then  =  (pr. 5.); which is contrary to the hypothesis. is not less than for if it were,  <  (pr. 18.) which is contrary to the hypothesis:

∴ >.

Q.E.D.