In every triangle, the largest side, is opposite the largest angle.
Also, the smallest side, is opposite the smallest angle.
a.
so 
,
because RQ is opposite angle P, the largest,
PR is opposite angle Q , the middle
and PQ is opposite angle R, the smallest.
Greatest side: RQ
b. The sum of the measures of the interior angles of any triangle is 180°,
so
thus, m(C) is the largest angle. This means the largest side is the side AB.
Answers:
a) RQ
b)AB
Also, the smallest side, is opposite the smallest angle.
a.
because RQ is opposite angle P, the largest,
PR is opposite angle Q , the middle
and PQ is opposite angle R, the smallest.
Greatest side: RQ
b. The sum of the measures of the interior angles of any triangle is 180°,
so
thus, m(C) is the largest angle. This means the largest side is the side AB.
Answers:
a) RQ
b)AB