Answer
$4$ inches
Work Step by Step
Put the given information into formulas. Use them to solve for $s$. $S^2$ is the equivalent of $s+2$ here. Find the square root of both sides and then isolate $s$ to get its values. Only the positive value matters since we are dealing with a shape.
$S=s+2$
$S^2=36$
$(s+2)^2=36$
$s+2=±6$
$s=-8,4$
$s=4$
