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4MA1/2F Jan 2022, Question 9: Angles in a Triangle

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2F (Foundation) · Calculator · 4 marks

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The question, in short

Using straight lines ABC, BDE and ADF with angle CBD = 132° and angle ADB = 58°, find x and y from the diagram.

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

Part (ai) · 1 mark

Write down the value of x shown at D between lines E and F.

  1. 1x and angle ADB are vertically opposite, so they are equal
  2. 2x = 58

Answer58

Part (aii) · 1 mark

State the geometric reason that justifies the value of x.

  1. 1Angles at a point where two lines cross are vertically opposite and equal

AnswerVertically opposite angle(s) are equal

Part (b) · 2 marks

Calculate the value of y at vertex A.

  1. 1Angles on a straight line add to 180°: angle ABD = 180 − 132 = 48°
  2. 2Angles in a triangle add to 180°: y = 180 − (58 + 48) = 74

Answer74

Stuck on a step? Read the free lesson: Angles in a Triangle

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