Mathematics for IGCSE & O level - Pythagoras' Theorem And Trigonometry (Section 4 - No. 32)
If side a = 7, side b = 8, and angle C = 60° in a triangle, what is the length of side c (rounded to two decimal places)?
7.42
7.00
3.00
13.00
คำอธิบาย
Using Cosine Rule: c^2 = a^2 + b^2 - 2ab*cos(C), c = 7.42