1. **Problem Statement:** Find the volume of the composite figure described with dimensions 15 km, 21 km, 9 km, and height 19 km. 2. **Understanding the figure:** The figure appears to be a composite prism-like shape. We can consider it as a rectangular prism with base dimensions 21 km by 15 km and height 19 km, plus an additional volume from a smaller rectangular section 9 km wide. 3. **Formula for volume of a rectangular prism:** $$V = \text{length} \times \text{width} \times \text{height}$$ 4. **Calculate the volume of the main prism:** $$V_1 = 21 \times 15 \times 19 = 5985 \text{ km}^3$$ 5. **Calculate the volume of the smaller prism section:** $$V_2 = 9 \times 15 \times 19 = 2565 \text{ km}^3$$ 6. **Total volume:** Since the smaller prism is part of the composite figure, if it is additive, total volume is sum: $$V = V_1 + V_2 = 5985 + 2565 = 8550 \text{ km}^3$$ 7. **Final answer:** The volume of the composite figure is $$\boxed{8550 \text{ km}^3}$$