Given that \( P=12, Q=5 \) and \( R=13 \) also \( \mathbf{P}+\mathb...

Given that \( P=12, Q=5 \) and \( R=13 \) also \( \mathbf{P}+\mathbf{Q}=\mathbf{R} \), then the angle between \( P \) and \( Q \) will be
(a) \( \pi \)
(b) \( \frac{\pi}{2} \)
(c) zero
(d) \( \frac{\pi}{4} \)