Question 36
Circle TheoremsPQRS is a cyclic quadrilateral in which PQ = PS. PT is a tangent to the circle and PQ makes an angle of 50° with the tangent as shown in the figure below. What is the size of QRS?

- A.50°
- B.40°
- C.110°
- D.80°
- E.100°.
Show the answer and explanation
Answer: E (100°.)
Explanation
By the alternate segment theorem <PSQ = 50°, and PQ = PS makes <PQS = 50° too, so <QPS = 80°. Opposite angles of a cyclic quadrilateral add to 180°, so <QRS = 100°.