0580/32 May/Jun 2021, Question 2: Describing Transformations
Cambridge IGCSE Mathematics 0580 · Paper 32 (Core) · Calculator · 13 marks
اقرأ هذا الحل مشروحاً بالعربي ←
The question, in short
Using four polygons drawn on a 1 cm² coordinate grid, identify the shaded shape, measure its area, describe three transformations, and draw a reflected image.
Summarised in our own words. Use the official paper for the exact wording and the diagram.
Part (a) · 1 mark
State the mathematical name of the shaded polygon.
- 1The shaded shape has 5 sides, so it is a pentagon
AnswerPentagon
Part (b) · 2 marks
Work out the area of the shaded polygon in cm².
- 1Vertices: (−2, 2), (−1, 4), (−2, 6), (−4, 6), (−6, 4)
- 2Surrounding rectangle from x = −6 to −1, y = 2 to 6: 5 × 4 = 20
- 3Corner triangles outside the shape: 1/2×1×2 + 1/2×1×2 + 1/2×2×2 + 1/2×4×2 = 8
- 4Area = 20 − 8 = 12
Answer12
Part (ci) · 2 marks
Describe fully the single transformation taking the shaded polygon to polygon A.
- 1Each vertex moves 7 right and 4 up, e.g. (−2, 2) → (5, 6)
- 2Translation by column vector (7, 4)
AnswerTranslation, column vector (7, 4)
Part (cii) · 3 marks
Describe fully the single transformation taking the shaded polygon to polygon B.
- 1Each point (x, y) maps to (−x, −y), e.g. (−2, 2) → (2, −2)
- 2Rotation, 180°, centre (0, 0)
AnswerRotation, centre (0, 0), 180°
Part (ciii) · 3 marks
Describe fully the single transformation taking the shaded polygon to polygon C.
- 1C is the same shape with sides half as long, so scale factor 0.5
- 2Lines joining matching vertices meet at (4, 2)
- 3Enlargement, centre (4, 2), scale factor 0.5
AnswerEnlargement, centre (4, 2), scale factor 0.5
Part (d) · 2 marks
Draw the shaded polygon's image after reflection in the line y = 0.
- 1Reflect in y = 0 (the x-axis): (x, y) → (x, −y)
- 2Plot (−2, −2), (−1, −4), (−2, −6), (−4, −6), (−6, −4) and join to make the pentagon
AnswerPentagon at (−2, −2), (−1, −4), (−2, −6), (−4, −6), (−6, −4)
Stuck on a step? Read the free lesson: Describing Transformations
Practise more describing transformations questions
Real 0580 past-paper questions, marked on your working like the exam, with a worked solution for every part.
Practise free on LemmaraMore past-paper questions on describing transformations
Also searched as: 0580/32/M/J/21 · 0580_s21_qp_32 · 0580 s21 32 · question 2.
Lemmara is an independent study tool, not affiliated with or endorsed by Cambridge International Education. The worked solutions are Lemmara’s own.