find the percent of the circle
r=radius of circle
then r=1/2 of the diagonal of the square
use some pythagoran theorme
45,45,90 triangle
(r√2)/2=1/2 of a side
r√2 is one side
square it
2r²=square
area of circle is pir²
percent it is is
square/circle=
(2r²)/(pir²)=
2/pi= about
0.636
about 64% that it is in the square