ECZ 2019 · O-Level Paper 1 — Circle Theorems

In the diagram below, A, B, C and D are points on the circumference of a circle, centre O. DÂT = 40°, BDC = 30° and AT is a tangent to the circle at A. Calculate (a) CBD.

Diagram for ECZ 2019 · O-Level Paper 1
  • A. 30°
  • B. 60°
  • C. 40°
  • D. 50°

Verified working — step 1

The tangent-chord theorem gives ∠ABD = ∠DAT = 40°.

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Original examination question © Examinations Council of Zambia. Worked solution and commentary © G12 Titan — not to be reproduced without permission.

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