Question

triangle PQR with side p across from angle P, side q across from angle Q, and side r across from angle RIf ∠P and ∠R are given, as well as the value of p, then explain whether the Law of Sines or the Law of Cosines should be used to solve for r.

Answer 1

in this problem we have that

$\frac{r}{sinR}=\frac{p}{sinP}$

therefore

The answer is

Law of Sines, two angles and an opposite side are known