Answer:
A
Step-by-step explanation:
The vertex of a parabola lies on the axis of symmetry.
Because the fence's dimensions is 30 feet by 10 feet, you can assume that one side of the pool is 30 feet while the other, non-congruent side, is 10 feet. The formula for perimeter, which you are trying to find, is 2L+2W=P. In this problem, 30 will be your L and 10 will be your W. Therefore, 2(30) +2(10)=80.
So 80 feet will be your answer.
Well, some integers can be irrational, but not all! :)