BOOK I. PROP. XXV. THEOR.
25
F two triangles have two sides (
and 
) of the one respectively equal to two sides (
and 
) of the other, but their bases unequal, the angle subtended by the greater base (
) of the one, must be greater than the angle subtended by the less base (
) of the other.
=, > or < 
is not equal to
for if = then = (pr. 4.)
which is contrary to the hypothesis;
is not less than
for if <
then < (pr. 24.),
which is also contrary to the hypothesis:
∴ > .
Q. E. D.
