1.18.5. Measurement of vertical angles

Try these first

1. 1.

   Define a vertical angle.

   Hint

   Think about how angles are measured above or below a flat surface.

2. 2.

   What is the purpose of the altitude bubble on a theodolite?

   Hint

   How do we check if something is straight?

3. 3.

   What is a vertical angle?

   • The angle above the horizontal plane
   • The angle below the horizontal plane
   • Both of the above

   Hint

   Consider what vertical angles represent.

4. 4.

   True or False: The altitude bubble should be off-center for accurate vertical angle measurements.

   • True
   • False

   Hint

   What happens to measurements if the bubble is not centered?

5. 5.

   A surveyor measures a vertical angle of elevation to the top of a building which reads 45° on the left face and 47° on the right face after averaging. What is the true vertical angle of elevation?

   Hint

   Remember to use the average of both readings!

6. 6.

   During a project, a surveying team records a vertical angle of depression to a lake as 30° and then rechecks from the opposite side to find 32°. What is the average depression angle?

   Hint

   Use the same averaging method as before.