Lemmara logoLemmaraWorked solution

4MA1/2H Jan 2021, Question 20: Area of a Triangle Using Sine

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 2H (Higher) · Calculator · 4 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

A regular hexagon ABCDEF has an equilateral triangle PQR cut out to leave shaded region T; P and Q lie on AB with AB = 1.5 × PQ. Given area of T is 72√3 cm², find PQ.

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

Solution · 4 marks

  1. 1Let PQ = x, so AB = 1.5x
  2. 2Triangle area = (√3/4)x²; hexagon area = 6 × (√3/4)(1.5x)² = (27√3/8)x²
  3. 3Area T: (27√3/8)x² − (√3/4)x² = (25√3/8)x² = 72√3
  4. 4x² = 72 × 8 ÷ 25 = 23.04
  5. 5PQ = √23.04 = 4.8

Answer4.8

Stuck on a step? Read the free lesson: Area of a Triangle Using Sine

Practise more area of a triangle using sine questions

Real 4MA1 past-paper questions, marked on your working like the exam, with a worked solution for every part.

Practise free on Lemmara

More past-paper questions on area of a triangle using sine

Also searched as: 4MA1 2H January 2021 · 4MA1/2H · 4ma1 jan21 2h · question 20.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.