1. **State the problem:** We need to find the total area of a compound figure made of two rectangles stacked vertically. 2. **Identify the dimensions:** - Top rectangle: width = 5 km, height = 9 km - Bottom rectangle: width = 3 km, height = 7 km 3. **Formula for area of a rectangle:** $$\text{Area} = \text{width} \times \text{height}$$ 4. **Calculate the area of the top rectangle:** $$5 \times 9 = 45 \text{ square kilometers}$$ 5. **Calculate the area of the bottom rectangle:** $$3 \times 7 = 21 \text{ square kilometers}$$ 6. **Add the areas to find the total area:** $$45 + 21 = 66 \text{ square kilometers}$$ 7. **Final answer:** The total area of the figure is **66 square kilometers**.