一“拼图”与“面积”携手——数形结合,验证规律利用剪拼前后的两个图形面积保持不变的性质,可以把同一个量(面积)用不同的方法表示出来,从而验证数学规律或公式.例1(内蒙古鄂尔多斯中考题)如图1-1,在边长为a的正方形纸片中剪去一个边长为b的小正方形,把余下的部分沿虚线剪开,拼成一个矩形(如图1-2),分别计算这两个图形阴影部分的面积,可以验证的乘法公式是(用字母表示). A “puzzle ” and “area ” hand in hand - combination of number, verify the law using the two graphics before and after the cut spell area remains the same nature, the same amount (area) can be expressed in different ways , To verify the mathematical laws or formulas.Example 1 (Inner Mongolia Erdos test questions) as shown in Figure 1-1, a square in the side length of the paper cut a small square b side length, the rest along the dotted line cut Open, spell into a rectangle (Figure 1-2), respectively, calculate the shadow area of ​​the two graphics area, multiplicative formula can be verified (with letters).