1. **State the problem:** Find the volume of a cylinder with height $7$ km and radius $8$ km. 2. **Formula for volume of a cylinder:** $$V = \pi r^2 h$$ where $r$ is the radius and $h$ is the height. 3. **Substitute the given values:** $$V = \pi \times 8^2 \times 7$$ 4. **Calculate the square of the radius:** $$8^2 = 64$$ 5. **Multiply the values:** $$V = \pi \times 64 \times 7$$ 6. **Simplify the multiplication:** $$V = \pi \times 448$$ 7. **Final volume:** $$V = 448\pi \text{ km}^3$$ This is the exact volume. If you want a decimal approximation, use $\pi \approx 3.1416$: $$V \approx 448 \times 3.1416 = 1407.45 \text{ km}^3$$ So, the volume of the cylinder is $448\pi$ cubic kilometers or approximately $1407.45$ cubic kilometers.