Juliana M. answered 09/14/19
BYU chemistry graduate with >2,000 hours of teaching experience
The area of a shape with 4 sides is just the width*height. In this case, both the width and height are 6.25 ft.
So A = 6.25 ft*6.25 ft = 39.0625 sq ft.
The answer should only have 3 significant figures, because the value given only had 3 significant figures to begin with. The answer is 39.1 sq ft.