1. **State the problem:** Calculate the total area of the compound figure composed of rectangles and squares with given side lengths in miles. 2. **Identify the shapes and dimensions:** The figure can be divided into three rectangles: - Bottom rectangle: length $15$ mi, height $3$ mi - Middle rectangle: length $9$ mi (since $15 - 6 = 9$), height $5$ mi - Top right rectangle: length $7$ mi, height $5$ mi 3. **Formula for area of a rectangle:** $$\text{Area} = \text{length} \times \text{height}$$ 4. **Calculate each area:** - Bottom rectangle area: $15 \times 3 = 45$ sq mi - Middle rectangle area: $9 \times 5 = 45$ sq mi - Top right rectangle area: $7 \times 5 = 35$ sq mi 5. **Sum the areas:** $$45 + 45 + 35 = 125$$ 6. **Final answer:** The total area of the compound figure is $125$ square miles.