ECZ 2019 · O-Level Paper 1 — Mensuration
The diagram below shows a sector AOB. Arc AB subtends an angle of 21° at the centre O. Given that the area of the sector is 14.85 cm2, calculate the radius. [π = 227]
- A. 9cm
- B. 14.85cm
- C. 7cm
- D. 81cm
Verified working — step 1
A sector with a 21° centre angle is 21360 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.
Have a different question?
Search it — if it is from a past paper or a school mock, chances are we have it worked out, or one that uses the same method.
Search any past-paper question