No, the radius is not 3.14 . The radius is 1/2 of the diameter . . . That's 6 feet.
If you see 3.14 on the sheet, then that's the number you're supposed to use for pi .
The area of any circle is (pi) x (radius squared).
If the table were a full circle, its area would be (pi) x (6 squared) = 36 pi square feet.
But it's only half of that . . . 18 pi = (18) x (3.14) = 56.52 square feet.
That's called the "area" of the table, not the "square feet" of the table.
And another thing: I see you're asking for the "closest" number. Don't ask me
how I know this, but I'm pretty sure that right under this question wherever you
copied it from, there's a list of choices, and when you posted the question, for
some reason you decided not to share the list.