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 BAD.

- A. 105°
- B. 75°
- C. 115°
- D. 130°
Verified working — step 1
ABCD is a cyclic quadrilateral, so angle BAD is supplementary to the opposite angle BCD. BCD is made of the two angles at C on either side of OC.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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