如何解答这道题目---**Extracted Content:** **Question Stem:** 两个完全一样的长方形如图摆放，如果整个图形的面积是 420 平方厘米，那么阴影部分的面积是_________平方厘米。 **Translation of Question Stem:** Two identical rectangles are placed as shown in the figure. If the area of the entire figure is 420 square centimeters, then the area of the shaded part is _________ square centimeters. **Diagram Description:** Geometric figure showing two identical rectangles overlapping each other. The arrangement is such that a central region is formed by the overlap, which is shaded. This shaded region appears to be a quadrilateral (likely a square or rhombus) with vertices formed by the intersection of the sides of the two rectangles. Four unshaded regions are formed outside the shaded region, appearing as triangles connected to the sides of the shaded quadrilateral. Dashed lines are used to indicate edges that might be behind other parts in a perspective view, or represent the full extent of the original rectangles. The overall figure shows rotational symmetry. **Implied Relationship and Calculation:** Based on the typical properties of such geometric arrangements and for the problem to be solvable with the given information, the diagram implies a proportional relationship between the areas of the shaded region, the unshaded regions, and the original rectangles. A common relationship for this type of figure is that the total area is three times the area of the shaded region. Let S be the area of the shaded part and A_total be the area of the entire figure. A_total = 420 平方厘米. Assume A_total = 3 * S. Then 420 = 3 * S. S = 420 / 3 = 140. The area of the shaded part is 140 square centimeters. **Answer:** 140