Question

The angle of depression on I-24 in Mont Eagle, Tennessee is 4°. For every mile of road (diagonally), what is the change in height in miles? In feet?

Answer 1

Check the picture below.

so that's the angle of depression, namely the angle below the horizontal.

if we use a diagonal mile only, namely hypotenuse = 1, as you see there, then we can check what the opposite side will be, in miles.

how many feet is that?

well, there are 5280 feet in 1 mile, so that'd be 0.069756 * 5280 ≈ 368.31 feet.