ECZ 2010 · O-Level Paper 1 — Circle Theorems
In the diagram, BD = 9 cm and DT = 3 cm, with ECT a tangent at C. Calculate the length of CT.
- A. 3 cm
- B. 9 cm
- C. 12 cm
- D. 6 cm
Verified working — step 1
BD passes through the centre, so BDT is a secant with TD = 3 and TB = 3 + 9 = 12. By the tangent-secant rule, CT2 = TD x TB = 3 x 12 = 36, so CT = …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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