10. The triangle $P Q R$ is inscribed in the circle $x 2 + y 2 = 25$. If $Q$ and $R$ have coordinates ( 3 , $4 )$ and $( - 4,3 )$ respectively, then $\angle P Q R$ is equal to: (A) $\pi / 2$ (B) $\pi / 3$ (C) $\pi / 4$ (D) $\pi / 6$
10. The triangle $P Q R$ is inscribed in the circle $x 2 + y 2 = 25$. If $Q$ and $R$ have coordinates ( 3 , $4 )$ and $( - 4,3 )$ respectively, then $\angle P Q R$ is equal to:\\
(A) $\pi / 2$\\
(B) $\pi / 3$\\
(C) $\pi / 4$\\
(D) $\pi / 6$\\