(Q19) Gopal is worrying that his neighbour can peep into his living room from the top floor of his house. He has decided raise the height of the fence that is high enough to block the view from his neighbour's top floor window. What should be the height of the fence? The measurements are given in the figure.

ECRQPABD8 m2 m1.5 m1.5 m1.5 m1.2 m

Solution :

In ∆ABD & ∆ACE

∠B = ∠C = 90o

∠A = ∠A (common angle)

∆ABD ∼ ∆ACE ( by AA similarity)

AB
AC
 =
BD
CE
⇒
=
BD
BD =
×
=
= m

Total height of the fence required is 1.5 m. + 0.3 m. = m to block the neighbour's view.