Answer: $42$

Explanation:1. Recall the formula for the circumference of a circle: The circumference $C$ of a circle can be expressed in terms of its diameter $d$ as: $C = \pi d$ Alternatively, in terms of its radius $r$, $C = 2\pi r$, where $d = 2r$.

2. Identify the given information: The circumference $C = 42\pi$ centimeters.

3. Substitute the given circumference into the formula involving diameter: $42\pi = \pi d$

4. Solve for the diameter $d$: Divide both sides of the equation by $\pi$: $\dfrac{42\pi}{\pi} = \dfrac{\pi d}{\pi}$ $42 = d$

5. State the answer: The diameter of the circle is $42$ centimeters.

6. Conclusion: The diameter, in centimeters, of the circle is $42$.