Chapter 10 - Area - 10-7 Areas of Circles and Sectors - Practice and Problem-Solving Exercises - Page 663: 8

$30.25 \pi \ cm^2$

Let $A$ be the area of a circle. The area $(A)$ of a circle whose radius is $R$ is given by: $A=\pi r^2 ...(1)$ We know that the radius is half of the diameter of a circle. That is, $r=\dfrac{d}{2}=\dfrac{11}{2}=5.5$ Plug the data in the equation (1) to obtain: $A=\pi (5.5)^2=\pi(30.25)$ Therefore, we get , $Area=30.25 \pi \ cm^2$