Question

# A rectangular swimming pool is three times as long as it is wide. If the perimeter of the pool is 320 feet, what are its dimensions?

Equations and inequalities
A rectangular swimming pool is three times as long as it is wide. If the perimeter of the pool is 320 feet, what are its dimensions?

2021-05-05
2021-08-04

Let x be the width of the rectangular swimming pool so that its width is 3x, both feet.
Since the perimeter is 320 ft, we can write:
$$\displaystyle{P}={2}{l}+{2}{w}$$
$$\displaystyle{320}={2}{\left({3}{x}\right)}+{2}{\left({x}\right)}$$
Solve for x. Divide both sides by 2:
$$\displaystyle{160}={3}{x}+{x}$$
$$\displaystyle{160}={4}{x}$$
$$\displaystyle{40}={x}$$
So, the dimensions of the rectangular swimming pool are:
120 feet by 40 feet