This is basically how they got the correct answer.
First they used the area formula:
[tex]\pi \times {r}^{2} [/tex]
So for you that would be:
[tex]\pi \times {9.8}^{2} [/tex]
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
