Question

Sally is having a problem with her puppy leaving the yard so she decides to build a new fence. The length of the yard is 10 feet more than 3 times the width. She needs 60 feet of fencing to do the job. Find the length of the yard.

Possible answers:
28 ft, 25 ft, 47.5 ft, 22 ft

Answer 1

The length of the yard is 25ft.

In order to find this we first need to set up variables for the length and the width. Since we don't know anything about the width, we'll set it as x. Then, we know the length is equal to ten more than three times the width. Since the width is x, we can write the length as 3x + 10. Now we can use the formula for the perimeter of a rectangle to solve for x.

2l + 2w = P

2(3x + 10) + 2(x) = 60

6x + 20 + 2x = 60

8x + 20 = 60

8x = 40

x = 5

Now that we have a value for x, we can plug into the length equation and find the length.

3x + 10

3(5) + 10

15 + 10

25