The length of the running track would be the perimeter of the figure.
In order to calculate the perimeter, we have to realize that two identical semicircles make of a whole circumference. Now, the radius of this circumference is one half of the length of the 56m side. Therefore, such radius is 28m.
Now, the perimeter of this circumference will be:
[tex]2\pi r\rightarrow2\cdot(3.14)\cdot(28)\rightarrow175.84m[/tex]To this lenght, we have to add up the remaining pair of linear segments, both measuring 91m
[tex]175.84m+91m+91=357.84[/tex]Therefore, we can conclude that: