1. **State the problem:** Find the volume of a cylinder with radius $r=8$ cm and height $h=20$ cm. 2. **Formula:** The volume $V$ of a cylinder is given by the formula: $$V = \pi r^2 h$$ where $r$ is the radius and $h$ is the height. 3. **Substitute values:** Substitute $r=8$ and $h=20$ into the formula: $$V = \pi \times 8^2 \times 20$$ 4. **Calculate:** $$V = \pi \times 64 \times 20$$ $$V = \pi \times 1280$$ 5. **Final answer:** $$V = 1280\pi \text{ cm}^3$$ This is the exact volume. If you want a decimal approximation, use $\pi \approx 3.1416$: $$V \approx 1280 \times 3.1416 = 4021.24 \text{ cm}^3$$