Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 1 - No. 19)
What information is required to use the formula Area = 1/2 * ab * sin C to find the area of a triangle?
The lengths of all three sides.
The length of two sides and the angle between them.
The lengths of two sides and any angle.
The lengths of one side and two angles.
Explication
You need the lengths of two sides and the angle between them.