From the right triangle, and using the definitions of the tangent and the cosine functions, we have:
[tex]\begin{gathered} \tan B=\frac{AC}{BC}=\frac{b}{a}\Rightarrow b=a\cdot\tan B...(1) \\ \\ \cos B=\frac{BC}{AB}=\frac{a}{c}\Rightarrow c=\frac{a}{\cos B}...(2) \end{gathered}[/tex]
From the problem, we identify:
[tex]\begin{gathered} B=55.7\degree \\ a=266\text{ km} \end{gathered}[/tex]
Finally, using these values, we can find b and c.
Using (1):
[tex]\begin{gathered} b=266\cdot\tan55.7\degree \\ \\ \therefore b=389.941\text{ km} \end{gathered}[/tex]
Using (2):
[tex]\begin{gathered} c=\frac{266}{\cos55.7\degree} \\ \\ \therefore c=472.028\text{ km} \end{gathered}[/tex]
