Explanation:
The radius and circumference of the dartboard can be obtained as follow
[tex]\text{radius}=\frac{1}{2}\times diameter=\frac{1}{2}\times8inches=4\text{ inches}[/tex]Radius = 4.00 inches
The circumference is obtained by
[tex]\begin{gathered} \text{Circumference}=\pi D \\ \text{Circumference}=3.14\times8=25.12\text{ inches} \end{gathered}[/tex]C