Question

A surveyor measures the distance across a straight river by the following method: Starting directly across from a tree on the opposite bank, he walks 118 m along the riverbank to establish a baseline. Then he sights across to the tree. The angle from his baseline to the tree is 36.0°. How wide is the river?

Answer 1

Answer:

W = 85.73 m

Explanation:

given,

surveyor walks = 118 m

makes an angle of = 36.0° with the tree

to find the width of the river

$tan \theta = \dfrac{W}{distance}$

$tan 36^0 = \dfrac{W}{118}$

$tan 36^0 = \dfrac{W}{118}$

$W = 118 \times 0.7265$

W = 85.73 m

hence, the width of the river is equal to W = 85.73 m