ECZ 2012 · O-Level Paper 1 — Trigonometry

In the diagram, AC = 10 cm, BC = 5 cm and angle ACB = 60°. Given that sin 60 = 0.866, cos 60 = 0.5 and tan 60 = 1.73, calculate the value of (AB)².

Verified working — step 1

The 60° sits BETWEEN the two known sides - exactly the cosine rule's setup, and the question even stops at (AB)².

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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