1. **State the problem:** We have a rectangle with length 16 m and width 12 m. We need to shade 30% of its area on the left side and label all side lengths and right angles. 2. **Calculate the total area of the rectangle:** $$\text{Area} = \text{length} \times \text{width} = 16 \times 12 = 192 \text{ m}^2$$ 3. **Calculate 30% of the area:** $$30\% = \frac{30}{100} = 0.3$$ $$\text{Shaded area} = 0.3 \times 192 = 57.6 \text{ m}^2$$ 4. **Determine the width of the shaded region on the left side:** Since the shaded area is a vertical strip on the left side, its width $w$ satisfies: $$w \times 12 = 57.6$$ $$w = \frac{57.6}{12} = 4.8 \text{ m}$$ 5. **Summary:** - The rectangle is 16 m long and 12 m wide. - The shaded region is a vertical strip on the left side with width 4.8 m and height 12 m. - All four corners are right angles. **Final answer:** The left 4.8 m width of the rectangle is shaded, representing 30% of the total area.