You are given a circle of radius 5 with center O.  A and B lie on the circle.  The length of arc AB is 6.  A square with side length x is inscribed in sector AOB such that one corner of the square is on OA, one corner on OB, and two corners on arc AB.  What is the area of the square (and therefore the value of x)?

In case the solution is not unique, what are the min/max values of x?