Answer to Question #140880 in Trigonometry for amy

Question

A surveyor has been given the job of finding the width of a river. She cannot measure the distance across the water, but she is able to obtain some measurements on land as shown in the diagram below. Based on her measurements, what is the width of the river?

Answer 1

Measure the distance along a line from a point directly opposite any landmark on the other bank to a point some distance upstream or downstream. Then measure the angle between that line and a sighting toward the original landmark.

Width of the river=(distance between the two points on your side of the river)*(tangent of the angle)