Given, sector angle `theta = 9=80^(@)`

and distance or radius r = 16.5 km

Area of sector `= (theta pi r^(2))/(360^(@)) = (80^(@) xx 3.14 xx (16.5)^(2))/(360^(@))`

`= (2 xx 3.14 xx 272.25)/(9) = (1709.73)/(9) = 189.97 km^(2)`

Which is the required area of the sea over which the ships are warned