Question 193050
Very  typical  problem
remember  Cir=2(pi)R,,,,and  Area  =  (pi)  r^2
by  finding  r,  the  problem  becomes  easy
given  cir  so  lets  start  there
c=2(pi)r=18(pi)
or 2*r=18
r=9

Area  = (pi) r^2=(pi) 9^2=81(pi)