Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 4 - No. 43)
If you know two sides and the included angle, which trigonometric rule would be most helpful to determine the length of the third side?
Sine Rule
Cosine Rule
Tangent Rule
None of the above
Wyjaśnienie
Cosine Rule helps find sides when you know SAS.