Sine:
You could leave it in an unsimplified form as such:
There are three sides of a triangle: a = 12, b, c
The angles are as such: A = 30o, B = 40o, C
\(a/\sin(A) = b/\sin(B) \Rightarrow 12/\sin(30°) = b/\sin(40°) \Rightarrow 12*\sin(40°) = b*\sin(30°) \Rightarrow b = (12*\sin(40°))/\sin(30°)\)
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