ECZ 2015 · O-Level Paper 1 — Similarity and Congruency
In the triangle shown, PQ = QR, angle QPR = (3x + 31)° and angle QRP = (91 − 2x)°. Find the size of angle PQR.
- A. 46°
- B. 67°
- C. 12°
- D. 44°
Verified working — step 1
PQ = QR makes the triangle isosceles with equal base angles: 3x + 31 = 91 − 2x ⇒ 5x = 60 ⇒ x = 12. Each base angle = 3(12) + 31 = 67°, so angle PQR = 180° − 2 × 67° = …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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