1. **State the problem:** We have a rectangle 24 meters long and want to find its width such that its area equals the area of a square with 12-meter sides. 2. **Formula for area:** - Area of rectangle = length \times width = $24 \times w$ - Area of square = side \times side = $12 \times 12 = 144$ 3. **Set areas equal:** $$24 \times w = 144$$ 4. **Solve for width $w$:** $$w = \frac{144}{24}$$ 5. **Simplify the fraction:** $$w = \frac{\cancel{144}^{6} \times 24}{\cancel{24}^1} = 6$$ 6. **Interpretation:** The width of the rectangle must be 6 meters to have the same area as the square. 7. **Answer:** The rectangle's dimensions are 24 meters by 6 meters, which corresponds to Option B.