Question 13
Circle TheoremsIn the diagram, POQ is the diameter of the circle centre O. Calculate ∠QRS

- A.35°
- B.70°
- C.100°
- D.125°
Show the answer and explanation
Answer: D (125°)
Explanation
∠PSQ = 90° (angle in a semicircle) and ∠SQP = 35°, so ∠SPQ = 55°. PQRS is cyclic, so ∠QRS = 180 − 55 = 125°.