Q12 of 107 Page 12

The height of a tower is 100 m. When the angle of elevation of the sun changes from 30° to 45°, the shadow of the tower becomes x metres less. The value of x is


Let AB be the tower of height 100 m


BC is the total distance of shadow formed at two different angles namely ACB and ADB 30° and 45° respectively


In Δ ACB


tan 30° =


= 100


a = 100


In Δ ADB


tan 45° =


100√3-x = 100


x = 100(√3-1) m

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