Angle of Elevation and Depression

Content

  • Angle of Elevation
  • Angle of Depression

Angle of Elevation

When an object above is looked from below angle of elevation is formed.

Example

Angle of elevation of the top of a tower from a point 25 m from its base is 75°. Find the height of the tower.

Let t be the height of the tower.

Consider the right angled triangle.

Tan 75° = t / 25

t = 25 x Tan 75°

t = 25 x 3.73

t = 93.25 m

Angle of Depression

When an object below is looked from above angle of depression is formed.

Example

James is standing on top of a watch tower and observing a boat which is at a distance of 500 m from the base of the tower. The angle of depression is 15°. Find the height of the watch tower.

Let t be the height of the watch tower.

Consider the right angled triangle.

Tan 15° = t / 500

t = 500 x Tan 15°

t = 500 x 0.27

t = 135 m