The area of the blue outer ring is given by the area of the entire circular archery less the area of the inner pink circle.
The area of a circle is given by
[tex]Area=\pi r^2[/tex], where [tex]r= \frac{d}{2} [/tex], r is the radius, d is the diameter.
Therefore, the area of the outer blue ring is given by:
[tex]Area=\pi\left( \frac{24}{2} \right)^2-\pi\left( \frac{6}{2} \right)^2 \\ \\ =\pi(12^2-3^2)=\pi(144-9) \\ \\ =135\pi\ in^2[/tex]
