In the diagram, POS and ROT are straight lines, OPQR is a parallelogram. |OS| = |OT| and ∠OST = 50°. Calculate ∠OPQ.

  • A 160o
  • B 140o
  • C 120o
  • D 100o
waec 2000mathematics

The correct answer is D. 100o

< T = < S = 50° (OS = OT)

< SOT = 180° - 2(50°) = 80°

< ROP = 80° (vertically opposite angle)

\(\therefore\) < OPQ = 180° - 80° = 100° (adjacent angles)

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