This is basically how they got the correct answer.
First they used the area formula:
So for you that would be:
Which equals
301.7
Since there's a hole in the circle we do the area of a square which is base times height.
Which is 3 x 3 = 9 for your problem
Then we subtract
301.7 - 9 = 292.7 !
Which is almost exactly 292.57 since there is a margin