What is the angle formed by the horizontal line with the line of sight of the observer to an object that is below?

Year 10 Interactive Maths - Second Edition

If the object is below the level of the observer, then the angle between the horizontal and the observer's line of sight is called the angle of depression.

Example 21

From the top of a vertical cliff 40 m high, the angle of depression of an object that is level with the base of the cliff is 34º.  How far is the object from the base of the cliff?

Solution:

Let x m be the distance of the object from the base of the cliff.

So, the object is 59.30 m from the base of the cliff.

Key Terms

angle of elevation, angle of depression