Question

If a boy is 5 ft. tall and his shadow is 4 ft. and the shadow of a flagpole is 16 ft., determine the height of the flagpole.

Answer 1

With the boy's given height and shadow length, we can set up a proportion.

height/shadow = 5/4
We can represent the height of the flagpole with the variable x.
5/4 = x/16
cross multiply
4x = 80
x= 20

The height of the flagpole is 20 ft.

Answer 2

The height of the flagpole is, 20 ft

Explanation:

Proportion states that two ratios or fractions are equal.

As per the statement:

If a boy is 5 ft. tall and his shadow is 4 ft. and the shadow of a flagpole is 16 ft.,

height of a boy = 5 ft

Shadow of a boy = 4 ft

Shadow of the flagpole = 16 ft

let height of the flagpole be h

then by definition we have;

`\frac{\text{height of a boy}}{\text{Shadow of a boy}}=\frac{\text{height of the flagpole}}{\text{Shadow of the flagpole}}`

Substitute the given values we have;

`(5)/(4) = (h)/(16)`

By cross multiply we have;

`80 = 4h`

Divide both sides by 4 we have;

`20 = h`

or

h = 20 ft

Therefore, the height of the flagpole is, 20 ft