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

Answer:

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

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,

            $tan 25 = \frac{z}{130}$

Now making  z the subject

           $z = 130 * tan (25)$

          $z = 60.62 \ m$