The boat is 338.7 feet away from the base of the cliff.
EXPLANATION
Let [tex]d[/tex] be the distance of the boat from the base of the cliff.
We can use alternate angles property to bring the angle of depression into the triangle.
Since the known side is opposite the [tex]42\degree[/tex] angle and the sede we are finding is adjacent to it, we use the tangent ratio.
From the diagram,
[tex] \tan42\degree =\frac{305}{d}[/tex]
[tex] d =\frac{305}{\tan42\degree}[/tex]
[tex] d =\frac{305}{\0.900}[/tex]
[tex] d =338.7[/tex]
Hence the boat is 338.7 feet away from the base of the cliff.
