ECZ 2024 · GCE Paper 1 — Mensuration
The diagram shows a sector AOB whose area is 34.65 cm2. The angle subtended at the centre is 81° and the radius is r cm. (π = 227) Find the radius (r) of the sector.
- A. 49 cm
- B. 14 cm
- C. 7 cm
- D. 4.95 cm
Verified working — step 1
A sector with an 81° centre angle is 81360 of the full circle, so its area is that fraction of πr2. Set this equal to 34.65 and dig r out.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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