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

Assuming the fish pond is round, what you're given is the circumference.

So you know that 2 πr = 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.