ECZ 2021 · O-Level Paper 1 — Mensuration
The diagram below shows a sector AOB with centre at O and radius 21cm. The angle subtended at the centre is θ and the area of the sector is 462cm2. Calculate the value of θ. [π = 227]
- A. 240°
- B. 90°
- C. 120°
- D. 60°
Verified working — step 1
A sector with centre angle θ is θ/360 of the full circle, so its area is that fraction of πr2. Substitute and make θ the subject.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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