Angle of Depression at Algebra Den

Arithmetic

Additive Identity
Arithmetic Progression
Associative Property
Averages
Brackets
Closure Property
Commutative Property
Conversion of Measurement Units
Cube Root
Decimal
Distributivity of Multiplication over Addition
Divisibility Principles
Equality
Exponents
Factors
Fractions
Fundamental Operations
H.C.F / G.C.D
Integers
L.C.M
Multiples
Multiplicative Identity
Multiplicative Inverse
Numbers
Percentages
Profit and Loss
Ratio and Proportion
Simple Interest
Square Root
Unitary Method

Algebra

Cartesian System
Order Relation
Polynomials
Probability
Standard Identities & their applications
Transpose

Geometry

Basic Geometrical Terms
Circle
Curves
Angles
Define Line, Line Segment and Rays
Non-Collinear Points
Parallelogram
Rectangle
Rhombus
Square
Three dimensional object
Trapezium
Triangle
Quadrilateral

Trigonometry

Trigonometry Ratios

Data-Handling

Arithmetic Mean
Frequency Distribution Table
Graphs
Median
Mode
Range

Videos
Solved Problems

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