Answer:
303
Step-by-step explanation:
Surface area of cone is [tex]=\pi r^{2} +\pi rl[/tex] , where l is the slant height.
Therefore the area of cone = [tex]3.14 \times( 9^{2}) +(3.14 \times9\times20)[/tex]
[tex]=302.6[/tex]
round off to nearest whole number, 303
