CST Level 1 Land Surveyor Certification Practice

Which angle measurement starts from the horizon and goes to the zenith?

1. Vertical angle

2. Azimuth angle

3. Deflection angle

4. Bearing angle

The correct answer is: Vertical angle

The angle measurement that starts from the horizon and goes to the zenith is indeed the vertical angle. Vertical angles are used to measure the angle of elevation or depression from a horizontal plane. When looking up from a horizontal line of sight to a point directly above (the zenith), the angle measured is called an angle of elevation; conversely, when looking down to a point below the horizon, the angle measured is referred to as an angle of depression. In surveying and related fields, understanding vertical angles is crucial for accurately determining the heights of objects, such as buildings or trees, and for establishing points at different elevations. This is a fundamental aspect of land surveying, which often requires measuring these angles to create topographic maps or engage in project analysis. The other types of angles mentioned, such as azimuth, deflection, and bearing angles, serve different purposes. Azimuth refers to a horizontal angle measured clockwise from a north reference, deflection angle measures the change in direction from one line to another, and bearing angle conveys direction in terms of north or south with an angle east or west. Each serves a significant role in navigation and surveying, but they do not relate to the vertical orientation as the vertical angle does.