Question

A surveyor measures the distance across a straight river by the following method. Starting directly across from a tree on the opposite bank, she walks d = 92 m along the riverbank to establish a baseline. Then she sights across to the tree. The angle from her baseline to the tree is θ = 37.0°. How wide is the river?

Answer 1

$w = d\tan\theta = 92\text{ m } \cdot \tan{(37.0\degree)} \approx 69.3\text{ m}.$