Question

A survey team is trying to estimate the height of a mountain above a level plain. From one point on the plain, they observe that the angle of elevation to the top of the mountain is 31. From a point 1000 feet closer to the mountain along the plain, they find that the angle of elevation is 34. How high (in feet) is the mountain?

Answer 1

5507.79 feet

Explanation:

To find the height of the mountain, we can draw triangles as in the image attached.

Let's call the height of the mountain 'h', and the distance from the first point (31 degrees) to the mountain 'x'.

Then, we can use the tangent relation of the angles:

tan(34) = h/x

tan(31) = h/(x+1000)

tan(31) is equal to 0.6009, and tan(34) is equal to 0.6745, so:

h/x = 0.6745 -> x = h/0.6745

using this value of x in the second equation:

h/(x+1000) = 0.6009

h/(h/0.6745 + 1000) = 0.6009

h = 0.6009 * (h/0.6745 + 1000)

h = 0.8909*h + 600.9

0.1091h = 600.9

h = 600.9 / 0.1091 = 5507.79 feet