The area of a circular sector is given by:
[tex]A=\frac{\theta}{360}\pi r^2[/tex]In this case each shaded part has an angle of 136°, this means that the total circular sector has a total angle of 272°, plugging this value and the value of the radius into the equation above we have:
[tex]A=\frac{272}{360}\pi(18)^2=769.06[/tex]Therefore the area of the shaded region is 769.06 squared cm and the answer is C.