1. What is the imaginary line between the eyes of the observer and the object being observed? A. Angle of Depression C. Horizontal Line B. Angle of Elevation D. Line of Sight 2. It is an acute angle formed by the eye level (horizontal line) and the line of sight when an observer looks at an object that is located at a lower level. A. Angle of Depression C. Inclination B. Angle of Elevation D. Reference Angle​