Given:
To find the angle Y, Use the cosine rule,
[tex]\begin{gathered} (^{}ZX)^2=(ZY)^2+(YX)^2-2(ZY)(YX)\cos Y \\ 599^2=400^2+320^2-2(400)(320)\cos Y \\ 358801-262400=-256000\cos Y \\ -\frac{96401}{256000}=\cos Y \\ Y=\cos ^{-1}(-\frac{96401}{256000}) \\ Y=112.1212^{\circ} \end{gathered}[/tex]
To find the angle where the airplane adjust its route to point Y,
It form the supplementary angle.
Answer: The angle where the airplane adjust its route to point Y is 67.88 degree (68).
