Question

Frank the Fence maker needs to fence in a rectangular yard. He fences in three of the four sides of the yard. The unfenced side of the yard is 40 feet long. The yard has an area of 280 square feet. What is the length, in feet, of the fence that Frank installs?

• A. $27$ feet
• B. $48$ feet
• C. $54$ feet
• D. $32$ feet

Answer 1

The correct option is C $54$ feet

54 feet: You know that one side of the yard is 40 feet long; call this the length. You also know that the area of the yard is 280 square feet. In order to determine the perimeter, you must know the width of the yard:

$A=l\times w$

$280=40w$

$w=280÷40=7feet$

Frank fences in the two 7-foot sides and one of the 40-foot sides. Thus, he needs 54 feet of fence: $40+7+7=54$ (Option C)