Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 3 - No. 19)
If you know two sides and the angle between them in a triangle, which is the best method to find the area?
Area = 1/2 * base * height
Area = 1/2 * ab * sinC
Cosine Rule
Pythagoras' theorem
Explication
The formula using two sides and the included angle is most appropriate.