The radius of the circle would be 5.5. The diameter of the circle would be 11. The area of the circle would be 30.25pi.
The formula for the radius of the circle is 2*pi*r. We can take 11 and divide it by two to get the radius. The diameter is equal to 2*radius. We can multiply 5.5 by 2 to get the diameter of 11. Or, some people find the circumference of the circle using pi*diameter. This way we have the diameter equal to 11. The area of a circle is equal to pi*r^2. We would take the radius, 5.5, and square it to get 30.25 pi