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” .

\tan \theta = \frac{opposite}{adjacent}

\tan45\degree=\frac{opposite}{15}

Opposite side = 15 meters

Height of the tower = 15 meters