Heights and Distances

Horizontal Level and Line of Sight

Line of sight is the line drawn from the eye of the observer to the point on the object viewed by the observer.

Horizontal level is the horizontal line through the eye of the observer.

Angle of elevation

The angle of elevation is relevant for objects above horizontal level.
It is the angle formed by the line of sight with the horizontal level.

To know more about Angle of elevation, visit here.

Angle of depression

The angle of depression is relevant for objects below horizontal level.
It is the angle formed by the line of sight with the horizontal level.

Calculating Heights and Distances

To, calculate heights and distances, we can make use of trigonometric ratios.

Step 1: Draw a line diagram corresponding to the problem.

Step 2: Mark all known heights, distances and angles and denote unknown lengths by variables.

Step 3: Use the values of various trigonometric ratios of the angles to obtain the unknown lengths from the known lengths.