ECZ 2025 · O-Level Paper 1 — Mensuration
In the following diagram, the sector OAB of a circle has radius r and angle AOB = 63°. Given that the area of the sector AOB is 66.55 cm2, calculate the radius. [π = 227]
- A. 10 cm
- B. 11 cm
- C. 12 cm
- D. 121 cm
Verified working — step 1
A sector with a 63° centre angle is 63360 of the full circle, so its area is that fraction of πr2. Substitute and solve for r.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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