Question

the angle of elevation of the top of a tower from certain point is 30°. if the observer moves 20 meters towards the tower the angle of elevation of top of tower increased by 15° . find the height of tower
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Answer 1

Let the height of tower be h m

Now In triangle ABD, we have,

=h/x=tan45°=h/x=1 =h=x------(1)

Now In triangle ABC, we have,

h/x+20=tan30°

h/h+20=1/√3----(from 1 equation)

=√3h=h+20

=h(√3-1)=20

=h=20/(√3-1)

=h=20/(√3-1)×(√3+1)/(√3+1)

=h=10(√3+1) m