The angle of elevation of an object is the angle a line of sight to the object makes above the horizontal, and the angle of depression is the angle of a line of sight to the object below the horizontal. We can find angles of elevation or depression using simple trigonometry. Consider the diagram below. The angle of elevation of the top of the tree from the groundis

We can use the diagram to draw the right angled triangle below.

The angle of elevationis the solution to

Conversely we might want to find the angle of depression of the point A on the ground from the top of the tree. We can draw the following diagram.

As before the angle of depression is the solution to