Make a diagram to see the relation between these two angles.
What is the relation between the angles of elevation and depression?
Practice makes perfect
Let's illustrate the situation that our classmate is trying to solve.
By definition, the elevation angle is the angle formed by a horizontal line and an observer's line of sight to an object above the horizontal line.
The angle of depression is the angle formed by a horizontal line and an observer's line of sight to an object below the horizontal line.
Notice that the two horizontal lines are parallel and the line of sight is a transversal. Therefore, by the Alternate Interior Angles Theorem, the angle of elevation and depression are congruent.
Our classmate found the angle of elevation, which means she already found the angle of depression. Then, to help her, we can ask her the following question.
What is the relation between the angles
of elevation and depression?
