Question 21
Triangles and QuadrilateralsIn the diagram below, TR = TS and ∠TRS = 60°. Find the value of x.

- A.30
- B.45
- C.60
- D.120
- E.150
Show the answer and explanation
Answer: C (60)
Explanation
TR = TS with ∠TRS = 60° makes triangle RST equilateral, so ∠RST = 60° and ∠PSR = 180° − 60° = 120°. PSRQ is cyclic, so x = 180° − 120° = 60°.