Question

The ratio of the perimeters of two rectangles is 5 to 8 . the perimeter of the larger rectangle is 72 inches. What is the perimeter of the smallest triangle?

Answer 1

45 inches

Explanation:

The 72 inches is 8 parts of the ratio, hence

`(72)/(8)` = 9 inches ← 1 part of the ratio

5 parts = 5 × 9 = 45 inches ← smaller perimeter

Answer 2

45 inches.

EXPLANATION

Let the perimeter of the smaller rectangle be x.

Then, the ratio of the perimeter of the smaller rectangle to the larger rectangle is

`x:72=5:8`

We change the ratio to fraction to obtain,

`(x)/(72) = (5)/(8)`

Multiply both sides by 72.

`x = (5)/(8) * 72`

`x = 5 * 9 = 45`

The perimeter of the smaller rectangle is 45 inches.