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0580/32 Feb/Mar 2024, Question 3: The Tangent Ratio

Cambridge IGCSE Mathematics 0580 · Paper 32 (Core) · Calculator · 13 marks

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The question, in short

Construct triangle DEF with DE = 6 cm and DF = 4.8 cm using ruler and compasses, keeping arcs, then answer grid triangle and isosceles triangle questions.

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

Part (a) · 2 marks

Using only a ruler and compasses, draw triangle DEF with DE = 6 cm and DF = 4.8 cm, keeping all construction arcs visible.

  1. 1Open compasses to 6 cm, centre E, draw an arc above EF
  2. 2Open compasses to 4.8 cm, centre F, draw an arc crossing the first arc
  3. 3The crossing point is D; join DE and DF with a ruler

AnswerCorrect triangle drawn with construction arcs

Part (bi) · 1 mark

From the grid, name the triangle that is exactly the same shape and size as triangle T.

  1. 1G has the same shape and size as T (rotated)
  2. 2G

AnswerG

Part (bii) · 1 mark

From the grid, name the triangle that has the same shape as T but a different size.

  1. 1F is an enlargement of T, same angles but larger
  2. 2F

AnswerF

Part (ci) · 3 marks

For the isosceles triangle with base 7 cm and base angles 62°, prove that the perpendicular height h is 6.58 cm to 3 significant figures.

  1. 1The height bisects the base: half base = 3.5 cm
  2. 2tan 62° = h ÷ 3.5
  3. 3h = 3.5 × tan 62° = 6.582…
  4. 4= 6.58 cm to 3 s.f.

Answerh = 7/2 × tan 62 = 6.582 to 6.583

Part (cii) · 3 marks

Work out the area of the isosceles triangle, giving the correct units.

  1. 1Area = 1/2 × 7 × 6.58
  2. 2= 23.03 = 23.0
  3. 3Units: cm²

Answer23.0 or 23.03 to 23.04, cm²

Part (ciii) · 3 marks

Using the arrangement of triangles meeting at centre O, show that a regular polygon cannot be formed.

  1. 1Angle at O = 180 − 2 × 62 = 56°
  2. 2Number of triangles = 360 ÷ 56 = 6.43…
  3. 36.43… is not a whole number, so the triangles cannot fit exactly round O
  4. 4So Kalpit cannot make a regular polygon

Answer360 ÷ (180 − 2 × 62) = 6.4…, which is not an integer

Stuck on a step? Read the free lesson: The Tangent Ratio

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Also searched as: 0580/32/F/M/24 · 0580_m24_qp_32 · 0580 m24 32 · question 3.
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