1. **State the problem:** We need to find the circumference of a circle with radius $r = 13$ m. 2. **Formula:** The circumference $C$ of a circle is given by the formula: $$C = 2 \pi r$$ where $\pi$ is approximately 3.14. 3. **Substitute the values:** $$C = 2 \times 3.14 \times 13$$ 4. **Calculate:** $$C = 2 \times 3.14 \times 13 = 81.64$$ 5. **Answer with units:** The circumference of the circle is $81.64$ m.