Geometry & MeasuresKey Facts

The Sine Rule

Part of Sine RuleGCSE Mathematics

This key facts covers The Sine Rule within Sine Rule for GCSE Mathematics. Revise Sine Rule in Geometry & Measures for GCSE Mathematics with 12 exam-style questions and 3 flashcards. This topic appears regularly enough that it should still be part of a steady revision cycle. It is section 2 of 4 in this topic. Use this key facts to connect the idea to the wider topic before moving on to questions and flashcards.

Topic position

Section 2 of 4

Practice

12 questions

Recall

3 flashcards

The Sine Rule

For sidesa/sin A = b/sin B = c/sin C
For anglessin A/a = sin B/b = sin C/c
Use whenYou have a side and its opposite angle, plus one more
RememberSide a is OPPOSITE angle A, etc.

Keep building this topic

Read this section alongside the surrounding pages in Sine Rule. That gives you the full topic sequence instead of a single isolated revision point.

Practice Questions for Sine Rule

Which of the following is the sine rule?

  • A. a/sinA = b/sinB = c/sinC
  • B. a² = b² + c² − 2bc cosA
  • C. Area = ½ab sinC
  • D. sinA/a = sinB/b + sinC/c
1 markfoundation

Explain what is meant by the ambiguous case of the sine rule, and state when it can occur.

3 markshigher

Quick Recall Flashcards

Sine Rule
a/sin A = b/sin B = c/sin C
Sine Rule
a/sinA = b/sinB = c/sinC. Use when you have a matched pair (side with opposite angle).

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