#### Answer

38.19 yd

#### Work Step by Step

Given A track is to be constructed around the football field at a
junior high school. If the straightaways are 100 yd in
length,
The total length around the track is 440yd
The total length of the track = 100 +100 + 2*Circumference of the two semi circles
= 100 + 100 + 2$\frac{2\pi r}{2}$
440 yd = 200 + 2($\pi$ r)
2($\pi$ r) = 440 -200
2($\pi$ r) = 240
$\pi$ r = $\frac{240}{2}$
r = $\frac{120}{\pi}$ = 38.19 yd