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对于一些组合图形,只要同学们亲自动手分一分、折一折、想一想,就会探寻到不同的解法。【例题】求正方形的面积:下图正方形ABCD的边长是12厘米,E、F、G、H分别是各边的中点,求阴影部分的面积。解法一:合并求和法。连接E、G两点,把阴影部分分成大小相同的两个等腰直角三角形(EHG和EFG),每个三角形底和正方形的边长相等,高是正方形边长的一半,根据三角形的面积公式,可以求出每个
For some combination of graphics, as long as the students personally get one point, one fold, think about it, we will explore different solutions. 【Example】 Find the area of the square: The length of the side of the square ABCD is 12cm, E, F, G, H are the midpoints of each side respectively, and find the area of the shaded area. Solution A: Merger and Summation Act. Connect points E and G, and divide the shaded parts into two isosceles right triangles (EHG and EFG) of the same size. Each triangle has the same side length and the same side of the square, and the height is half the length of the square. According to the triangle area formula , You can find each one