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” .

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


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

      

                     Opposite side = 15 meters

                Height of the tower = 15 meters