Answer: [tex]9\pi\ in.[/tex]
Step-by-step explanation:
Given
The diameter of a circle is [tex]d=9\ in.[/tex]
So, the radius is [tex]r=\frac{d}{2}=4.5\ in.[/tex]
The circumference is given by [tex]2\pi r[/tex]
Insert the values
[tex]\Rightarrow 2\pi \cdot 4.5\\\Rightarrow 9\pi \ in.[/tex]
Thus, the circumference of the circle is [tex]9\pi\ in.[/tex]