A) $ 90{}^\circ -\frac{\angle B}{2} $
B) $ 90{}^\circ +\frac{\angle C}{2} $
C) $ 90{}^\circ -\frac{\angle A}{2} $
D) $ 90{}^\circ +\frac{\angle B}{2} $
Correct Answer: A
$ \therefore $ $ \angle RQP+\angle RBP=180{}^\circ $ $ \angle RQP=180{}^\circ -\angle RBP $ (i) Now, $ \angle RBP=\angle RBA+\angle B+\angle CBP $ $ \angle RBP=\frac{\sqrt{C}}{2}+\angle B+\frac{\angle A}{2} $ (ii) Put value of $ \angle RBP $ in Eq. (i), we get $ \angle RQP=180{}^\circ -( \frac{\angle C}{2}+\angle B+\frac{\angle A}{2} ) $ $ =180{}^\circ -( \frac{\angle A+\angle B+\angle C+\angle B}{2} ) $ $ =180{}^\circ -( \frac{180{}^\circ +\angle B}{2} ) $ $ =180{}^\circ -90{}^\circ -\frac{\angle B}{2}=90{}^\circ -\frac{\angle B}{2} $