California Assessment of Student Performance and Progress (CAASPP) Math Practice Exam

When an observer gazes at a point above them, what is being measured?

1. The angle of depression

2. The angle of elevation

3. The angle of inclination

4. The angle of trajectory

The correct answer is: The angle of elevation

When an observer gazes at a point above them, what is being measured is known as the angle of elevation. This concept refers to the angle formed by the observer's line of sight and the horizontal line extending from the observer’s eye level. Specifically, the angle of elevation quantifies how much above the horizontal plane the observed point is situated. When an observer looks straight ahead, their line of sight is horizontal, and as they look up towards an object, the angle between this line of sight and the horizontal increases, forming the angle of elevation. This is crucial in various applications such as surveying, aviation, and even in everyday scenarios like determining the height of a tree or building. Other terms mentioned may refer to different contexts. The angle of depression is the angle formed when looking down from a horizontal line to a lower point. The angle of inclination usually pertains to the angle from horizontal in a broader context, such as a line or surface. The angle of trajectory is specific to the path followed by a projectile and is not generally used in the context of direct observation. Therefore, the measurement relevant to looking upwards at a point is specifically the angle of elevation.