1. The problem is to find the surface area or volume of an open half-cylinder with a given length of 455 cm. 2. To solve this, we need more information such as the radius of the cylinder's base. 3. The formulas for a half-cylinder are: - Surface area (open): $$A = \pi r l + 2 r l$$ where $r$ is radius and $l$ is length. - Volume: $$V = \frac{1}{2} \pi r^2 l$$ 4. Since only the length $l=455$ cm is given, we cannot calculate the surface area or volume without the radius. 5. Please provide the radius to proceed with calculations.