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0580/23 Oct/Nov 2025, Question 10: Pythagoras' Theorem

Cambridge IGCSE Mathematics 0580 · Paper 23 (Extended) · Non-calculator · 4 marks

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The question, in short

Right-angled triangle ABC has the right angle at A, with AB = 8 cm and BC = 11 cm. Find the exact length of AC and the value of k where cos x = k.

Summarised in our own words. Use the official paper for the exact wording and the diagram.

Part (a) · 3 marks

Calculate the exact length of side AC in the right-angled triangle with AB = 8 cm and BC = 11 cm.

  1. 1BC is the hypotenuse: 11² = AC² + 8²
  2. 2AC² = 121 − 64 = 57
  3. 3AC = √57 cm

Answer√57

Part (b) · 1 mark

Given cos x = k, state the value of k for angle x at B.

  1. 1cos x = adjacent/hypotenuse = AB/BC
  2. 2k = 8/11

Answer8/11

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Also searched as: 0580/23/O/N/25 · 0580_w25_qp_23 · 0580 w25 23 · question 10.
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