Answer:
60.161714 meters
Explanation:
The triangle is superimposed over the river, the side in question is the side opposite to the angle that was measured. We are given the adjacent side of the angle. We can use the tangent function to solve this...
Tan x = (opposite side)/(adjacent side)
Here we have
Tan 76 = x/15 solve for x...
15(tan 76) = x (multiply by both sides by 15 to get rid of the fraction)
Crunch this with your calculator...
60.161714 = x