Lemmara logoLemmaraWorked solution

4MA1/1H Jun 2021, Question 22: Trigonometry in 3D: Cuboids

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 1H (Higher) · Calculator · 4 marks

اقرأ هذا الحل مشروحاً بالعربي ←

The question, in short

In a prism with triangular ends and horizontal base ABEF, using AC = BC = FD = ED = 12 cm, AB = 10 cm and BE = 15 cm, work out the angle AD makes with the base, to 3 significant figures.

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

Solution · 4 marks

  1. 1M is the midpoint of FE; D is directly above M, so the angle needed is DAM
  2. 2FM = 10 ÷ 2 = 5, so AM = √(5² + 15²) = √250 = 15.81…
  3. 3Height DM = √(12² − 5²) = √119 = 10.91…
  4. 4tan DAM = 10.91… ÷ 15.81…
  5. 5Angle DAM = 34.6

Answer34.6

Stuck on a step? Read the free lesson: Trigonometry in 3D: Cuboids

Practise more trigonometry in 3d: cuboids 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 trigonometry in 3d: cuboids

Also searched as: 4MA1 1H June 2021 · 4MA1/1H · 4ma1 jun21 1h · question 22.
Lemmara is an independent study tool, not affiliated with or endorsed by Pearson Edexcel. The worked solutions are Lemmara’s own.