Question

Jillian measured the distance around a small fish pond as 27 yards. Which would be a good estimate for the distance across the pond 14 yards 9 yards or 7 yards

Answer 1

Assuming the fish pond is round, what you're given is the circumference.
So you know that 2πr = 27.
We want to solve for the diameter, or d = 2r. We should isolate that.
2r = 27/π
2r = 8.59 yards, or ~9 yards.