triangle PQR with side p across from angle P, side q across from angle Q, and side r across from angle R If r, p, and q are given, then explain whether the Law of Sines or the Law of Cosines should be used to solve for ∠Q. Law of Cosines, two sides and the included angle are known Law of Cosines, all sides are known Law of Sines, two sides and an opposite angle are known Law of Sines, two angles and the included side are known