Explanation
Opposite sides are 5 miles each and for each semicircle we have:
[tex]\frac{2\pi *\frac{1}{2}}{2}=\frac{\pi}{2}\text{ miles}[/tex]
Then the lenght of the track is:
[tex]5+5+\frac{\pi}{2}+\frac{\pi}{2}=10+\pi[/tex]
Approximately 13.1416 miles
