Q5 of 12 Page 203

An aeroplane at an altitude of 200 m observes the angle of depression of opposite points on the banks of a river to be 45° and 60°. Find in metres the width of the river.

The figure is given below:



Let, Height of the aeroplane from the ground = AB = 200m


Width of the river = AB


In right triangle CAO,




AO = 200m ……(1)


In triangle CBO,


∠ CBO = 60°






……(2)


width of the river = AB = AO + OB


=




m = 315.47 m


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