Answer:

1456 yards

Step-by-step explanation:

We can imagine a rectangle with a semicircle in each of its short sides.

The length of the field is 100 yards with a width of 40 yards.

Notice that the two semicircles on both ends form a circle with diameter 40 yards. Since it's diameter is 40, then it's radius is 20. We can get the length of the rectangle by subtracting two 20 from 100 or subtracting it's diameter to the entire length 100:

100-20-20=100-40=60

Since we formed a rectangle with two semicircles on both ends, we have the length of the rectangle 60 yards and the width 40 yards.

We first get the circumference of the circle.

C=πd

=(3.14)(40)=125.6

Then we get the measure of the two lengths of the rectangle which is 60

60+60=120

We multiply 145.6 by 10 we get 1456