From the uploaded image, we see a circle with a radius of $9 \, \text{in}$. Using this information, we can calculate both the diameter ($D$) and the circumference ($C$).

Step 1: Diameter

The formula for the diameter of a circle is: $D = 2r$ Where $r$ is the radius.

Substituting $r = 9 \, \text{in}$: $D = 2 \times 9 = 18 \, \text{in}$

Step 2: Circumference

The formula for the circumference of a circle is: $C = 2\pi r$

Substituting $r = 9 \, \text{in}$: $C = 2\pi \times 9 = 18\pi \, \text{in}$

If we approximate $\pi \approx 3.1416$: $C \approx 18 \times 3.1416 = 56.5488 \, \text{in}$

Final Answer:

• Diameter: $D = 18 \, \text{in}$
• Circumference: $C = 18\pi \, \text{in}$ or approximately $56.55 \, \text{in}$.

Would you like a breakdown of these calculations or further clarifications?
Here are some follow-up questions:

1. How is the formula for circumference derived from the circle's geometry?
2. Can you calculate the area of the circle with the same radius?
3. What would happen to the circumference if the radius were doubled?
4. How does the value of $\pi$ affect calculations of circles?
5. Can you use a different approximation for $\pi$, like $3.14$, to compare results?

Tip: Remember, $\pi$ is an irrational number, so using more decimal places improves the precision of your results!