Question

A lighthouse has a shadow that is 36 feet long. Zara is 4 feet tall, and she is standing next to the lighthouse. Zara has a shadow that is 3 feet long. Use this information to complete the statement about the lighthouse

Answer 1

48 feet

Explanation:

At a particular time, objects and their shadows are proportionate.

Therefore, in figure,

AB/FD = BC/DE --- (1)

where AB is the height of the lighthouse, BC, its shadow and FD is the height of Zara and DE is her shadow.

From the given information,

BC = 36 feet

FD = 4 feet and DE = 3 feet

(1) becomes

AB/4 = 36/3

AB = 12

AB = 48

Hence, the height of the lighthouse is 48 feet.