At a certain time of day the angle of elevation of the sun is 80 degrees. To the nearest foot find the height of a tree whose shadow is 40 feet long.

In this case, we'll have to carry out several steps to find the solution.
Step 01:
Data:
angle of elevation = 80°
shadow of the tree = 40 ft
Step 02:
right triangle:
tan α = opposite / adjacent
α = 80°
opposite = height of the tree = x
adjacent = shadow of the tree = 40 ft
tan 80° = x / 40 ft
40 ft * tan 80° = x
226.85 ft = x
The answer is:
height of the tree = 227 ft