A large dining room table is in the shape of a semi circle diameter 12 feet. What is the square feet closest to the area? Radius-3.14

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.