Page:First six books of the elements of Euclid 1847 Byrne.djvu/73

Rh RIANGLES ( and ) on equal bases and between the same parallels are equal.



= (pr. 36.);

but = twice  (pr. 34.),

and = twice  (pr. 34.),

∴ =  (ax. 7.).

Q. E. D.