In the diagram, O is the centre of the circle where OS//QR and ∠SOR = 35o

  • A 35o
  • B 45o
  • C 55o
  • D 70o
waec 2004mathematics

The correct answer is C. 55o

∠SOR = ∠ORQ alternate angle.

Also ∠OQR = ∠OQR (Base angle of isosceles)

∠QOR = 108 – 2(35o) = 180 - 70o - 110o ∠QPR = 1/2QOR = 1/2(110o) ∠QPR + 55o (theorem angle at center is twice angle at circumference)

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