ECZ 2026 · GCE Paper 1 — Circle Theorems
The points A, B, C and D are on the circumference of a circle centre O such that angle OBC = 50° and angle OCD = 25°. BT is a tangent to the circle at B. Find angle BDC.
- A. 80°
- B. 50°
- C. 25°
- D. 40°
Verified working — step 1
Angle BDC stands on chord BC, and so does the angle at the centre, BOC. Find BOC from the isosceles triangle OBC, then halve it.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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