First, find the radius
2[tex] \pi [/tex]r=circumference
r=18 [tex] \pi [/tex] cm
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2[tex] \pi [/tex]
r=9 cm
Now, we can just use the circle area formula to solve
[tex] \pi [/tex][tex]r^{2} [/tex]
=[tex] \pi [/tex] [tex] 9^{2} [/tex]
=81 [tex] \pi [/tex]
=254.469 cm^2