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Home >> Trigonometry Ratios >> Find Height, Distance using T - Ratios >> Angle of Depression >>

## Angle of Depression

 Angle of Elevation Angle of Depression

Before you study this topic you should know what is angle of elevation and depression:

What is Angle of Depression ?

The formulas we used in angle of depression :

To find height and distance we use Cot θ = Adjacent Side / Opposite Side

Example 1 : A person is standing on a tower which is 5m high and is looking at the ball down, the angle of depression is 45°. Find how far is the ball
Solution : Let AB is the tower. A is the top and B is the foot of tower. C is the point on the ground where the ball is placed and is making a angle of depression of 45°

If we draw a picture it will look like as below -

So we get
AB (Height) = 5m
∠ DCA (Angle of depression at point C) = 45°
Distance BC = ?

We know that Cot θ = Adjacent Side / Opposite Side

cot 45° = BC / AB
1 = BC / 5
BC = 5 x 1 = 5 meters
So the ball is 5 meters away from the tower

### Study More Solved Questions / Examples

 From the top of mountain 40 metres above sea, the angle of depression of a ship is 15°. Find how far is the boat

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