To find the area of the circle, you can use the formula:
\[ \text{Area} = \pi r^2 \]
where \( r \) is the radius of the circle. The radius is half of the diameter. Given that the diameter is 140 ft, the radius is:
\[ r = \frac{140}{2} = 70 \text{ ft} \]
Now, plug the radius into the area formula, using \( \pi \approx 3.14 \):
\[ \text{Area} = 3.14 \times (70)^2 \]
Calculating \( (70)^2 \):
\[ 70^2 = 4900 \]
Now, multiply:
\[ \text{Area} = 3.14 \times 4900 = 15,386 \]
Thus, the area of the circle is:
\[ 15,386 \text{ ft}^2 \]
The correct response is:
15,386 ft².