Question

Refer to the rectangle shown. Suppose the width of 4 inches is decreased by 3 inches.
a. Find the percent of change in the perimeter.
b. Find the percent of change in the area.

Answer 1

Answer:

a.  30% decrease in perimeter

b.  75% decrease in area

Step-by-step explanation:

Before decrease:

  Perimeter = 2L + 2W = 2(6) + 2(4) = 12 + 8 = 20

  Area = L * W = 6 * 4 = 24

After decrease:

  Perimeter = 2L + 2W = 2(6) + 2(1) = 12 + 2 = 14

  Area = L * W = 6 * 1 = 6

Percent of change in the perimeter:

20 - 14 = 6

6/20 = 0.3 or 30% decrease in perimeter

Percent of change in the area:

24 - 6 = 18

18/24 = 0.75 or 75% decrease in area