When should you use the sine rule and when should you use the cosine rule?

The sine rule can be used when we either know:a) the length of two sides A and B and an angle that is not the corner where A and B meetb) two angles and the length of one side
The cosine rule can be used when we know:a) all three side lengths orb) when we have the length of sides A and B and the angle of the corner where A and B meet

JB
Answered by Joseph B. Maths tutor

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