Answer:
Christopher needs 24 feet of fencing. Your rectangle should be 5x7 feet.
Explanation:
Line PO is 5 feet wide, and we know that the side across from it is 5 feet wide. 5+5=10. The longer sides are supposed to be 2 feet longer than the shorter sides, so they have to be 7 feet long. 7+7=14. 10+14=24.