In $\triangle P Q R$, the sum of $\angle P$ and $\angle Q$ is $60^{\circ}$. The measure of $\angle R$ is
(A) $60^{\circ}$
(B) $300^{\circ}$
(C) $120^{\circ}$
(D) $30^{\circ}$
(E) $40^{\circ}$
The sum of the three angles in any triangle is always $180^{\circ}$.

In $\triangle P Q R$, the sum of $\angle P$ and $\angle Q$ is $60^{\circ}$, and thus $\angle R$ must measure $180^{\circ}-60^{\circ}=120^{\circ}$.