Question 1194689
<br>
An "irregular field that is in the shape of two squares, side by side" suggests that the side lengths of the two squares are different; so the field looks something like this:<br><pre>

  +-----------+
  |           |
  |           +-----+
  |           |     |
  |           |     |
  +-----------+-----+</pre><br>
or perhaps this:<br><pre>
  +-----------+
  |           +-----+
  |           |     |
  |           |     |
  |           +-----+
  +-----------+</pre><br>

Let x and y be the side lengths of the larger and smaller square, respectively.<br>
Then the combined area of the two squares is<br>
{{{x^2+y^2}}}<br>
The perimeter of the field is<br>
{{{3x+3y+(x-y) = 4x+2y}}}<br>
So we need to solve a pair of simultaneous equations:<br>
(1) {{{x^2+y^2=17396}}}
(2) {{{4x+2y=572}}}<br>
You can solve the pair of equations by solving (2) for y and substituting in (1); you will get an ugly quadratic equation whose solutions you would probably need a calculator for.<br>
Since a calculator was going to be necessary, I solved the problem by a different path.<br>
I used the TABLE feature of a TI-83 calculator to find integer solution(s) of<br>
{{{x^2+y^2=17396}}} --> {{{y=sqrt(17396-x^2)}}}<br>
and found there was only one: x=100 and y=86.<br.
And that satisfied the condition that the perimeter 4x+2y is 572.<br>
From there, I can't answer the question that was asked.  If the field looks like the first diagram above, the longest side of the field is 100+86=186 yards; if it looks like the second diagram, the longest side of the field is 100 yards.<br>
ANSWER: The longest side of the field is either 100 yards or 186 yards<br>