Considering the amount of PI (3.14) your equation would be written like this for the top portion
6x3.14ft^2
18.84ft^2
Now all you have to do is multiply 18.84ft by 2 giving you the answer of 37.68
Same thing for the circumference, almost
18.84ft with the height of 6ft.
Given. I would have to say Area of Base has the most volume