Answer :
Given data:
The given diameter of the circle is D=18 in.
The expression for the circumference is,
[tex]C=\pi D[/tex]Substitute the given values in the above expression.
[tex]\begin{gathered} C=\pi(18\text{ in)} \\ =56.52\text{ in} \end{gathered}[/tex]Thus, the circumference of the circle is 56.52 in.