Question 967609
Hint:


Let the square have a side length of x. Let x be some measurement in yards.


That means each semi-circle has a diameter of x, so each semi-circle has a radius of x/2


Here is what the drawing would look like


<img src = "http://i150.photobucket.com/albums/s91/jim_thompson5910/figure1_zpslnopaunc.png">


The area of the square is {{{x^2}}} square yards.


If you take the two semi-circular ends and glue them together, you would form a full complete circle. The area of this circle is {{{pi*r^2=pi*(x/2)^2}}} square yards.


So in total, the complete area of this oval is {{{x^2+pi*(x/2)^2}}}


"the total area of the field is 1,300 square yards" which tells us that 


{{{x^2+pi*(x/2)^2 = 1300}}}


solve that equation for x to get your answer.