1. **State the problem:** We have an L-shaped figure composed of three rectangles. We know the dimensions and areas of two rectangles and the area of the third rectangle. We need to find the missing side length labeled "? in". 2. **Identify known values:** - Top rectangle: length = 11 in, area = 39 in² - Left rectangle: height = 9 in, area = 30 in² - Bottom right rectangle: area = 20 in² - Missing side length = ? in 3. **Find the widths and heights of the known rectangles:** - For the top rectangle, area = length × width, so width = area / length = $\frac{39}{11} = 3.545$ in - For the left rectangle, area = width × height, so width = area / height = $\frac{30}{9} = 3.333$ in 4. **Determine the missing side length:** - The bottom right rectangle shares the same height as the top rectangle's width (3.545 in) minus the left rectangle's width (3.333 in), so height = $3.545 - 3.333 = 0.212$ in - The area of the bottom right rectangle is 20 in², so its missing side length (width) = area / height = $\frac{20}{0.212} \approx 94.34$ in 5. **Final answer:** The missing side length is approximately **94.34 in**.