Question 77121
What I decided to do is divide the square into 4 equal squares.
Then I look at just 1 circle inside its own square, tangent to 
the sides with 4 areas left over in the corners.
The area of the circle is {{{pi*r^2 = 25*pi}}}
The area of the square is {{{10*10 = 100}}}
The area of 1 of the 4 corner areas is {{{(100 - 25*pi) / 4}}}
In the center, ther are 4 of these little corner areas,
so the center area is {{{4*(100 - 25*pi) / 4 = 100 - 25*pi}}}
{{{100 - 25*pi = 21.5}}} in2 answer
To check the answers, there are 16 of the {{{(100 - 25*pi) / 4}}}
areas in all, so 4 circles + {{{4*(100 - 25*pi)}}} should equal
{{{20*20 = 400}}}
{{{4*25*pi + 4*(100 - 25*pi) = 400}}}
{{{314.16 + 4*21.46 = 400}}}
{{{314.16 + 85.84 = 400}}}
{{{400 = 400}}}
OK