Let the radius of this circle be R.
The approximate rectangle has a length equal to half of the circumference and a width equal to the radius of the circle.
therefore
[(2πR/2)+R]*2-2πR=6
(πR+R)*2-2πR=6
2πR+2R-2πR=6
2R=6
R=3
Area of a circle
=πR*R
=π*3*3
=9π
=28.26 square centimeters