Question

1.5 m tall boy stands at a distance of 30 m from a lamp post and casts a shadow of 4.5 m on the ground . Find the height of the lamp post

Answer 1

Answer:

2.5m

Step-by-step explanation:

let AB be the height of boy =1.5

CD the lamp =let it be x

OB be the shadow =4.5

BD distance from lamp = 30m

in ΔAOB

tan∅ =AB/OB

In ΔCOD

tan∅ =CD/OD =CD/(OB+BD)

∴AB/OB =CD/(OB+BD)

1.5/4.5=CD/4.5+3

CD=7.5/3 = 2.5m