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ABCD is a cyclic quadrilateral. Diagonals AC and BD meets at P. If ∠APB = 110° and ∠CBD = 30°, then ∠ADB measures
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- 55°
- 30°
- 70°
- 80°
- 55°
Correct Option: D
∠APB = 110° = ∠CPD
∴ ∠APD = 180° – 110° = 70° = ∠BPC
∴ ∠PCB = 180° – 70° – 30° = 80°
Angles subtended by same arcs at the circumference are equal.
∴ ∠ACB or ∠PCB = ∠ADB = 80°
