Question

At a certain time of day, a pole, 5 meters tall, casts a 3-meter tall shadow. The shadow of a building next to the pole is 18 meters long. How tall is the building?

Answer 1

Length of the building = 30 meters

Explanation:

Given:

Length of pole = 5 meters

Length of shadow of pole = 3 meters

Length of shadow of the building = 18 meters

To find length of the building.

Solution:

On drawing the figure of the given situation, we get two similar triangles.

Applying proportionality theorem of similar triangles.

`(AB)/(BC)=(DE)/(EC)`

Plugging in the given lengths.

`(AB)/(18)=(5)/(3)`

Multiplying both sides by 18.

`(AB)/(18)* 18=(5)/(3)* 18`

`AB=(90)/(3)`

`AB=30`

Thus, length of the building = 30 meters