Angle of Depression

Definition of Angle of Depression

  • Angle of depression is the angle between a horizontal line and the line joining the observer's eye to some object beneath the horizontal line.

Examples of Angle of Depression

Solved Example on Angle of Depression

An airplane is flying at an altitude of 1000 m. From the plane the angle of depression of a tree on the ground is measured as 15°. What is the distance from the plane to the tree?


A. 3,864 m

B. 3,732 m

C. 1,035 m

D. 1,000 m

Correct Answer: A


Step 1: Let x be the distance from the plane to the tree.

Step 2: Since the horizontal lines are parallel, the angles of elevation and depression are equal in measure.

Step 3:

Step 4:

Step 5: x = 3,864 m

Step 6: So, the distance from the airplane to the tree is 3,864 m.


Related Terms for Angle of Depression

  • Angle
  • Horizontal Line

Additional Links for Angle of Depression