1. **Problem statement:** Find the surface area of a cone with a base diameter of 8 cm and a slant height of 13.6 cm. 2. **Formula:** The surface area $A$ of a cone is given by $$A = \pi r^2 + \pi r l$$ where $r$ is the radius of the base and $l$ is the slant height. 3. **Calculate the radius:** Since the diameter is 8 cm, $$r = \frac{8}{2} = 4 \text{ cm}$$ 4. **Substitute values into the formula:** $$A = \pi (4)^2 + \pi (4)(13.6)$$ 5. **Simplify:** $$A = \pi \times 16 + \pi \times 54.4 = 16\pi + 54.4\pi = (16 + 54.4)\pi = 70.4\pi$$ 6. **Calculate numerical value:** $$A \approx 70.4 \times 3.1416 = 221.2$$ 7. **Round to nearest whole number:** $$A \approx 221$$ **Final answer:** The surface area of the cone is approximately 221 square centimeters.