Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 6 - No. 29)
What is the significance of the angle C within the area formula for a triangle: Area = 1/2 * a * b * sin C?
It is the angle opposite side c.
It is the right angle of the triangle.
It is the included angle between sides a and b.
It is any angle of the triangle.
Explication
Angle C must be between sides a and b.