Question

A surveyor measures the distance across a river that flows straight north by the following method. Starting directly across from a tree on the opposite bank, the surveyor walks distance, D = 130 m along the river to establish a baseline. She then sights across to the tree and reads that the angle from the baseline to the tree is an angle θ = 25°. How wide is the river?

Answer 1

The width of the river is
`z = 60.62 \ m`

Step-by-step explanation:

From the question we are told that

The distance of the base line is D = 130 m

The angle is
`\theta = 25^o`

A diagram illustration the question is shown on the first uploaded image

Applying Trigonometric Rules for Right-angled Triangle,

`tan 25 = (z)/(130)`

Now making z the subject

`z = 130 * tan (25)`

`z = 60.62 \ m`