 Krishna
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Step 1:  Analyse the given data.

Key words to understand the question.

• A line joining the eye of the observer and object viewed by the observer. This line is called “line of sight”.

• The line of sight is above the horizontal line and angle between the line of sight and the horizontal line is called angle of elevation.

• The line of sight is below the horizontal line and angle between the line of sight and the horizontal line is called angle of depression.

Step 2: When we want to solve the problems of heights and distances, we should consider the following:

• All the objects such as towers, trees, buildings, ships, mountains etc. shall be considered as linear for mathematical convenience.

• The angle of elevation or angle of depression is considered with reference to the horizontal line.

• The height of the observer is neglected, if it is not given in the problem.

Step 3: According to the given data make a imaginary figure.

GIVEN: Angle of elevation = 45\degree

Distance between the foot of the tower and the observation point = 15 meters

Height of the tower = ? AB - tower height

Step 4:  Find the suitable trigonometric ratio to calculate the height of the tower

NOTE: We know the adjacent side and we need to find the opposite side.

Hence we need to consider the trigonometric ratio “tan” .