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.
- 1Open compasses to 6 cm, centre E, draw an arc above EF
- 2Open compasses to 4.8 cm, centre F, draw an arc crossing the first arc
- 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.
- 1G has the same shape and size as T (rotated)
- 2G
AnswerG
Part (bii) · 1 mark
From the grid, name the triangle that has the same shape as T but a different size.
- 1F is an enlargement of T, same angles but larger
- 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.
- 1The height bisects the base: half base = 3.5 cm
- 2tan 62° = h ÷ 3.5
- 3h = 3.5 × tan 62° = 6.582…
- 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.
- 1Area = 1/2 × 7 × 6.58
- 2= 23.03 = 23.0
- 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.
- 1Angle at O = 180 − 2 × 62 = 56°
- 2Number of triangles = 360 ÷ 56 = 6.43…
- 36.43… is not a whole number, so the triangles cannot fit exactly round O
- 4So Kalpit cannot make a regular polygon
Answer360 ÷ (180 − 2 × 62) = 6.4…, which is not an integer
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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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