1. **Problem statement:** We are given two vertices of a rectangular park at coordinates $(-3,5)$ and $(-3,-4)$, and we need to find the area of the park in square kilometers. 2. **Understanding the rectangle:** The rectangle has vertices at $(-3,5)$, $(1,5)$, $(1,-4)$, and $(-3,-4)$ as described. 3. **Formula for area of a rectangle:** $$\text{Area} = \text{length} \times \text{width}$$ 4. **Find the length:** The length is the vertical distance between $(-3,5)$ and $(-3,-4)$. $$\text{length} = |5 - (-4)| = |5 + 4| = 9$$ 5. **Find the width:** The width is the horizontal distance between $(-3,5)$ and $(1,5)$. $$\text{width} = |1 - (-3)| = |1 + 3| = 4$$ 6. **Calculate the area:** $$\text{Area} = 9 \times 4 = 36$$ 7. **Final answer:** The area of the park is $36$ km$^2$.