Brenda is building a rectangular pen for her dog. She has enough fencing to build the pen so that it has a perimeter of 36 feet. She wants the pen to have an area of 65 ft2. What are the dimensions of the dog pen?

Question

Brenda is building a rectangular pen for her dog. She has enough fencing to build the pen so that it has a perimeter of 36 feet. She wants the pen to have an area of 65 ft2. What are the dimensions of the dog pen? 
A. 5 feet by 13 feet
B. 10 feet by 8 feet
C. 9 feet by 9 feet
D. 65 feet by 1 foot

Steve · Answer

Since 65 = 5x13, try that to see whether it fits the required perimeter. Only A and D could even possibly be a choice.