Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 4 - No. 41)
What are the two scenarios where you can use the cosine rule?
When you know all the sides.
When you know two sides and the included angle.
When you know one side and two angles.
When you know the length of the base and height.
Shpjegimi
The cosine rule can be applied when all three sides are known or when two sides and the included angle are known.