Answer: Required equation :
Dimensions of the pen:
Width = 12 feet and Length =36 feet.
Step-by-step explanation:
Let w be the width of rectangular pen, then the length of the rectangular pen will be 3w.
We know that the perimeter of rectangle is given by "2length+2width".
Perimeter of rectangular pen = 2(3w)+2(w) =6w+2w=8w (1)
Given : You have 96 feet of fencing to enclose a rectangular pen for your dog.
i.e. Perimeter of rectangular pen = 96 feet (2)
From (1) and (2), we get
[Divide both sides by 8]
Thus, width = 12 feet and length = 3(12)=36 feet.