EXPLANATION
To solve the question, we will have to sketch the image
We are to use the sketch above to compute the height y
[tex]tan31^0=\frac{opposite}{adjacent}=\frac{y}{5.2km}[/tex]Then, we will make y the subject of the formula
[tex]\begin{gathered} y=5.2\times\text{ tan31} \\ y=5.2km\times0.6009 \\ y=3.124km \end{gathered}[/tex]Therefore, the value of the height will be 3.1km