1. The problem asks for the circumference of a circle with a diameter of 13 cm. 2. The formula for the circumference $C$ of a circle is given by: $$C = \pi d$$ where $d$ is the diameter. 3. Substitute the given diameter $d = 13$ cm into the formula: $$C = \pi \times 13$$ 4. Using the approximation $\pi \approx 3.1416$, calculate: $$C \approx 3.1416 \times 13 = 40.8408$$ 5. Round the answer to 1 decimal place: $$C \approx 40.8 \text{ cm}$$ Therefore, the circumference of the circle is approximately 40.8 cm.