1. **Stating the problem:** We have a 3D box with dimensions: length = 12.50 m, width = 10.50 m, height varies with 50 cm on the front side and 70 cm on the back side, and vertical edges on the side and back are 70 cm. 2. **Understanding the dimensions:** Convert all measurements to the same unit for consistency. Since length and width are in meters, convert heights from centimeters to meters: $$50\text{ cm} = 0.50\text{ m}$$ $$70\text{ cm} = 0.70\text{ m}$$ 3. **Interpreting the shape:** The box is not a perfect rectangular prism because the front and back heights differ (0.50 m front, 0.70 m back). This suggests a slanted or trapezoidal side. 4. **Calculating volume (approximate):** For a box with varying height, approximate volume by averaging the heights: $$\text{Average height} = \frac{0.50 + 0.70}{2} = 0.60\text{ m}$$ Then, $$\text{Volume} = \text{length} \times \text{width} \times \text{average height} = 12.50 \times 10.50 \times 0.60$$ 5. **Calculate:** $$12.50 \times 10.50 = 131.25$$ $$131.25 \times 0.60 = 78.75$$ 6. **Final answer:** The approximate volume of the box is $$\boxed{78.75\text{ cubic meters}}$$ This method assumes a linear slope between front and back heights, which is common in such shapes.