Question

a 150 cm tall boy stands at a distance of 8m from a lamp post and cast a shadow of 2m find the height of the lamp post

Answer 1

Hi !!!! here' s ur answer. hope helps you.

Let AB be boy = 1.5m

CD be lamp = Let it be x m.

OB be shadow cast by boy = 4.5m

BD be distance between boy and lamp = 3m

Therefore

In ΔAOB,

=> tan θ = AB/OB

In ΔCOD,

=> tan θ = CD/OD = CD/(OB+BD)

∴ AB/OB = CD/(OB+BD)

=> 1.5/4.5 = CD/(4.5+3)

=> CD = 7.5/3 = 2.5m