Pg 634 (566) - Q19
If one angle in a trianble is larger than another angle, then the
side opposite that angle is longer than the side opposite the smaller angle.
Knowing this, we can deduce from PQ > QR that angle r must be greater than
60°. Since all the angles must add up to
180°, and we already have two angles at 60° or greater,
angle q° must be smaller than 60°. Referring back to the
rule about the length of sides opposite their angles, side PR (which is
opposite to q°) must therefore be smaller than side QR (opposite 60°).
Essentially, because q < 60°, PR < QR.