求解---Here is the extracted content from the image: **Problem Title:** [附加题] (10分) **Question Stem:** 一个正方形, 如果先截去宽 2 分米的长方形, 又截去宽 4 分米的长方形 (如图), 面积比原来减少 40 平方分米。原来正方形的边长是多少分米? **Translation of Question Stem:** An original square, if a rectangle with width 2 decimeters is first cut off, and then a rectangle with width 4 decimeters is cut off (as shown in the figure), the area is reduced by 40 square decimeters compared to the original. What is the side length of the original square in decimeters? **Mathematical Calculations Shown in Image:** 40 + (2 x 4) = 48 48 ÷ (2 + 4) = 8 **Chart/Diagram Description:** * **Type:** Geometric figure. * **Main Elements:** * A large implied square shape, representing the original square. * A smaller, unshaded rectangle within the large square, representing the remaining area after cuts. * Two shaded rectangular strips bordering the unshaded rectangle, representing the areas cut off. * One shaded strip is shown along one side (e.g., top or bottom) and labeled with a width of "2 分米" (2 decimeters). * Another shaded strip is shown along an adjacent side (e.g., left or right) and labeled with a width of "4 分米" (4 decimeters). * The diagram visually depicts the two strips being cut from adjacent sides of the original square, resulting in an overlapping rectangular region where the two strips would intersect. This overlapping region is implicitly a rectangle with dimensions 2 decimeters by 4 decimeters. * The labels "2 分米" and "4 分米" are placed next to the corresponding shaded strips, indicating their widths. **Other Relevant Text/Annotations:** * A circled number "116". * Some scribbled text or numbers near the circled "116" (e.g., a shape resembling "Z", and "27").