Question 308447
if you draw the square inside the circle the squares four corners are each a point on the circle. the radius is drawn from the center of the circle to a point on the circle. so draw 2 radiuses to 2 points on one side of the square which will create an isosoles triangle since the raduis counts as 2 of the sides.

now the r=3
so side one=3 , side two=3 , side three=?
{{{a^2+b^2=c^2}}}
{{{a=3}}}
{{{b=3}}}
c= one side of the square
{{{3^2+3^2=c^2}}}
{{{9+9=c^2}}}
{{{18=c^2}}}
{{{sqrt(18)=sqrt(c^2)}}}
{{{sqrt(18)=c}}}
Area of square is {{{s^2}}} s=side
{{{(sqrt(18))^2=A}}}
{{{highlight(18=A)}}}