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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