Question

A biologist wants to know the width w of a

river in order to properly set instruments for
studying the pollutants in the water. From
point A, the biologist walks downstream l =102 feet and sights to point C. From this
sighting, it is determined that _ = 60_.


How wide is the river?
Answer in units of f

Answer 1

Use tangent to solve.
tan(60 degrees) = O/A
A = 102
Solve for O
O = tan(60 degrees)(102)
= 176.7 ft.