You can put this solution on YOUR website! I hope you know what is the apothem of a regular polygon. If not just google it.
Ok, let us inscribed a circle in a regular polygon so that its radius is equal to the apothem.
The formula of Regular polygon Circumscribing a circle are: and
In the perimeter formula, see that , substitute it to the Area: where r = 6
Therefore, Area = 144 sq. unit.