To calculate the circumference of a circle, you can use the formula:
\[ C = \pi \times d \]
where \(C\) is the circumference and \(d\) is the diameter.
Given that the diameter is 25 yards, you can substitute this value into the formula:
\[ C = \pi \times 25 \text{ yds} \]
Using the approximate value of \(\pi \approx 3.14\):
\[ C \approx 3.14 \times 25 \text{ yds} \approx 78.5 \text{ yds} \]
Therefore, the circumference of the circle is approximately 78.5 yards.