Find the value of θ in the diagram
...Find the value of θ in the diagram
60o
100o
120o
30o
Correct answer is C
Using cosine formula (t√3)2 = t2 + t2 - 2t2 cosθ
3t2 = 2t2 - 2t2 cosθ = 2t2(1 - cosθ)
1 - cosθ = 3t22t2 = 32
cos = 1 - 32=−12
θ = cos-1(-12) = 120o and 240o
N.B 0 ≥ θ 360