From a point on the ground, the angles of elevation of the bottom and the top of a transmission tower fixed at the top of a 20 m high building are 45° and 60° respectively. Find the height of the tower


As per the question:

Let the height of building = p = 20 m


Therefore, total height of building and transmission tower = p’


The angle of elevation to the top of the building = 45° and that to the top of transmission tower = 60°


Height of transmission tower = ?


1st case:






2nd case:





Now, the height of the tower can be calculated as:


p'- p = 20√3 - 20


= 20(√3 - 1)


= 20(1.732 - 1)


= 20 × 0.732


= 14.64 m


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