Many application problems involving right triangles mention the angle of depression and angle of elevation. The angle of depression is angle measured below the horizontal, and may also be called the angle of declination. The angle of elevation is the angle measured above the horizontal (see figure below), and may also be called the angle of inclination.
Let’s start with a couple of basic angle of elevation problems:
The next example is a little more complex than the ones shown above, since it involves working with more than one
right triangle and it’s an angle of depression problem. See if you can solve the question on your own before viewing its solution:
Finally, not all trigonometric ratio problems you encounter will be angle of elevation or depression-based. Here’s an example involving two right triangles facing one another.