A rectangular field is nine times as long as it is wide.

Question

A rectangular field is nine times as long as it is wide. If the perimeter of the field is 1200 feet, what are the dimensions of the field?

Answer 1

That is the correct answer. The steps are:

#! Express the given information about L and W as an equality

#2 Express the perimeter in terms of L & W

#3 Substitute L or W from #1 into #2

#4 Solve for a numerical value of L or W using #1

#5 State L and W as numbers.

#6 Check your answer by substituting the numerical L and W into #2

The key to questions such as this is to express the given information as algebraic statements. In

this case steps #1 and #2.

Answer 2

Perimeter of a rectangle = 2L + 2W. For this rectangle L = 9W because the length is 9 times the width. P = 1200 ft.

Substituting: 1200 = 2(9W) + 2W -> 1200 = 18W + 2W = 20W

W = 1200/20 = 60 ft. Then L must be 9(60) = 540 ft.

You can check the result by plugging the two dimensions back into the perimeter equation to see if it's really 1200 ft as specified.