You can't tell the dimensions from the area. There are an infinite number of correct answers. The length of the fence is 2 times (length of the pond + width) and the length and width can be anything, just as long as their product is 2956.5 .
If you want to know how fast the professional runner is going, you need to multiply 3 1/3 by 1 1/4 since the professional is 1 1/4 times faster. So, your answer is 4 1/6.
Green area - triangle area = 72-9 = 63 square feet