Answer:
18π[tex]cm^{2}[/tex]
Step-by-step explanation:
Firstly we will have to find the area of the whole circle so we do....
[tex]A_{circle} =[/tex] π[tex]r^{2}[/tex]
[tex]A_{circle} =[/tex] [tex]9^{2}[/tex]π
[tex]A_{circle} =[/tex] 81π[tex]cm^{2}[/tex]
If we are talking about a whole circle the angels in the middle will be equal to 360°. But in our case we are only talking about 80° out of 360°. In other words we have to find out the area what [tex]\frac{80}{360}[/tex] (in other words [tex]\frac{2}{9}[/tex] )from the whole area is equal to. So we do....
81π[tex]cm^{2}[/tex] x [tex]\frac{2}{9}[/tex] = 18π[tex]cm^{2}[/tex]
