Sine rule: finding an angle (ambiguous case)

Sample Sine rule: finding an angle (ambiguous case) questions

A few of the 4 questions, from easier to harder. Choose your exam board and tier to practise them, with every answer marked.

1. Question 13 marksGrade 8-9
   In triangle ABC, angle A = 40°, side a = 6.1 cm (opposite angle A), and side b = 7.4 cm (opposite angle B). Find angle B, correct to 1 decimal place. This triangle has two possible cases - give both possible values of angle B.

What are the common mistakes in Sine rule: finding an angle (ambiguous case)?

When a pupil makes one of these on Revision Workshop, the marking engine names the mistake and explains it, instead of just marking the answer wrong.

• Finds only one valid solution in an ambiguous-case (e.g. sine rule) situation where a second solution also exists

  Only found the acute-angle solution from $\sin^{-1}$ - since angle A is acute and $a < b$ but $a > b\sin A$

Quick answers about Sine rule: finding an angle (ambiguous case)

How many Sine rule: finding an angle (ambiguous case) practice questions are there?

There are 4 self-marking GCSE and IGCSE Maths questions on Sine rule: finding an angle (ambiguous case), written for AQA, Pearson, OCR, Pearson International GCSE Maths A (4MA1), Cambridge IGCSE Mathematics (0580), Cambridge IGCSE (9-1) Mathematics (0980) across Higher and Extended tier. Each one is marked instantly and has a full worked solution.

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