First you have to figure out the length of the track:
[tex] 2 * \pi * r [/tex]
r is the half of the diameter:
200ft : 2 = 100ft
[tex] 2* \pi *100ft [/tex] = 200[tex] \pi [/tex]≈ 628,31
The athlete has to run ca. 5280ft for one mile:
5280 : 628,31≈8,4
The athlete has to run 8,4 laps
