Answer:
a. the diameter is 127.324 yards
b. The area is 12732.385 yards^2
Explanation:
The circumference of the circle is 400, and to get circumference from diameter, multiply it by π, so we divide by pi to get the diameter. 400/π = 127.324
The area of a circle is πr^2. To find r, or radius, divide the diameter by 2 to get 63.662. So it is 63.662^2π. 63.662^2 = 4052.844, so 4052.844π, and now we get 12732.385