1. **State the problem:** We need to find the volume of a prism given the area of its cross-section and its length. 2. **Formula:** The volume $V$ of a prism is given by the formula: $$V = \text{Area of cross-section} \times \text{Length}$$ 3. **Given values:** - Area of cross-section $= 90$ cm$^2$ - Length $= 11$ cm 4. **Calculate the volume:** $$V = 90 \times 11$$ $$V = 990$$ 5. **Interpretation:** The volume of the prism is $990$ cm$^3$. This means the prism can hold $990$ cubic centimeters of space.