Question 887215
r is radius for the circle.
{{{pi*r^2}}} is the circle area.


The square is some side, x.
{{{x^2}}}, area of the square.


Given these areas equal,  {{{pi*r^2=x^2}}}
{{{x=sqrt(pi*r^2)}}}
{{{x=r*sqrt(pi)}}}


Perimeter of the square is {{{4x=highlight(4r*sqrt(pi))}}}.
Circumference of the circle, {{{highlight(2pi*r)}}}.
From these, arrange the ratio any way of the two that you want.