4024/13 May/Jun 2025, Question 3: Angles in a Triangle
Cambridge O Level Mathematics 4024 · Paper 13 (Non-calculator) · Non-calculator · 3 marks
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The question, in short
Use angle facts on a straight line and in an isosceles triangle to find the unknown angles x and y.
Summarised in our own words. Use the official paper for the exact wording and the diagram.
Part (a) · 1 mark
Angles on a straight line with one angle 37°; find x.
- 1Angles on a straight line add to 180°
- 2x = 180 − 37 = 143
Answer143
Part (b) · 2 marks
Isosceles triangle PQR with PQ = PR and angle QPR = 46°; find y, the angle at Q.
- 1PQ = PR, so angle PQR = angle PRQ (base angles of an isosceles triangle)
- 2y = (180 − 46) ÷ 2 = 134 ÷ 2 = 67
Answer67
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Also searched as: 4024/13/M/J/25 · 4024_s25_qp_13 · 4024 s25 13 · question 3.
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