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4MA1/1FR Jan 2022, Question 2: Classifying Triangles

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 1FR (Foundation) · Calculator · 3 marks

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The question, in short

Three shapes are shown: a triangle, a rectangle and a regular polygon. Identify the triangle type, mark the rectangle's symmetry lines, and state the polygon's rotational symmetry order.

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

Part (a) · 1 mark

Give the correct mathematical term for the triangle shown.

  1. 1The two sloping sides of shape A are marked with a single dash each, so those two sides are equal in length.
  2. 2A triangle with exactly two equal sides is isosceles.
  3. 3Shape A is an isosceles triangle.

AnswerIsosceles

Part (b) · 1 mark

Draw all lines of symmetry on the rectangle.

  1. 1A line of symmetry folds the shape exactly onto itself.
  2. 2Folding the rectangle about the line joining the midpoints of the top and bottom edges maps it onto itself, so that vertical line is a line of symmetry.
  3. 3Folding it about the line joining the midpoints of the left and right edges also maps it onto itself, so that horizontal line is a line of symmetry.
  4. 4A diagonal of a rectangle is not a line of symmetry.
  5. 5Draw exactly 2 lines on shape B: one vertical through the midpoints of the top and bottom edges and one horizontal through the midpoints of the left and right edges.

AnswerTwo lines: one vertical line through the midpoints of the top and bottom edges, and one horizontal line through the midpoints of the left and right edges

Part (c) · 1 mark

State how many rotational symmetry positions the regular polygon has.

  1. 1Shape C is a regular pentagon, so it has 5 equal sides and 5 equal angles.
  2. 2Turning it through 360° ÷ 5 = 72° maps it onto itself.
  3. 3In one full turn it fits onto itself 5 times.
  4. 4The order of rotational symmetry of shape C is 5.

Answer5

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