The problem asks for the circumference of a circle with a diameter of 28 cm, using $\pi = 3.14$.

The formula for the circumference $C$ of a circle is:

$C = \pi \times d$

Where:

• $\pi = 3.14$
• $d$ is the diameter of the circle.

Given $d = 28 \, \text{cm}$, the circumference is:

$C = 3.14 \times 28 = 87.92 \, \text{cm}$

So, the circumference is 87.92 cm.

Let me know if you want further details or have any questions!

Here are five related questions:

1. What is the area of this circle using the same diameter?
2. How would the circumference change if the diameter were doubled?
3. How do you calculate the circumference if the radius is given instead of the diameter?
4. What is the formula to convert circumference into radius or diameter?
5. Why do we use 3.14 as an approximation for $\pi$?

Tip: Remember, the diameter is always twice the radius, and using the radius makes certain calculations easier in some cases!