Question 1064339
Diagonal of the square is equal to diameter of the circle.


Ratio of circumference of the CIRCLE to the area of the CIRCLE:{{{(2pi*r)/(pi*r^2)}}}


{{{(pi*r*2)/(pi*r*r)}}}


{{{highlight(2/r)}}}---------For ANY circle.




The square and circle that you and your in-law has, the square is 9 inches^2, so side length is 3.
The diagonal, {{{sqrt(3^2+3^2)=sqrt(2*9)=3*sqrt(2)}}}.
Radius {{{r=(3/2)sqrt(2)}}}.


For this diagonal or diamete  {{{3sqrt(2)/2}}}, the ratio of circumference to area is {{{2/(3sqrt(2)/2)=4/(3sqrt(2))}}}
{{{(4/3)sqrt(2)/2}}}


{{{(2/3)sqrt(2)}}}