ECZ 2021 · O-Level Paper 1 — Circle Theorems

The points A, B, C and D are on the circumference of a circle centre O, such that angle AOC = 126°. AO is parallel to DC and angle OCB = 33°. Find (b) OCD.

Diagram for ECZ 2021 · O-Level Paper 1
  • A. 126°
  • B. 72°
  • C. 63°
  • D. 54°

Verified working — step 1

The parallel lines are the key: AO and DC are parallel, and OC crosses both as a transversal.

The full step-by-step working and final answer are included with Premium — checked against ECZ marking standards.

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

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