Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 3 - No. 29)
What is the formula for finding the area of a triangle if two sides, *a* and *b*, and the *included* angle *C* are known?
Area = a * b * sin C
Area = 1/2 * a * b * cos C
Area = 1/2 * a * b * sin C
Area = (a + b + c) / 2
คำอธิบาย
Area = 1/2 * a * b * sin C is correct.