HELLO!!!
If the diameter is 12, this means that the radius is half of that amount (6)
In order to find area of a circle, you must solve pi x r^2 pi is 3.16 and the radius is 6. 6 ^2 is 36.
36x (pi) is 113.09 which should round off to 113.1 This means that area of the circle is 113.1 cm.
I Hope This Help & good luck.