在解几何题的过程中,若能掌握轴对称(图形),中心对称(图形)的概念和性质,不仅能够提高学生的思维分析能力,开阔学生视野,而且巧妙应用这些知识解答实际问题,可以使思路更加简捷清晰,减少很多烦琐的步骤,大大缩短解题过程。下面举例说明。例1如图1,已知点O是平行四边形ABCD的对称中心,EF和GH经过点O,EF分别交AB、CD于点E,F,GH分 In the process of solving geometry problems, if we can grasp the concept and nature of symmetry (graph) and centrosymmetry (graph), we can not only improve students ’ability of thinking analysis but also broaden students’ horizons, and cleverly apply the knowledge to solve practical problems, Make the idea more simple and clear, reduce a lot of cumbersome steps, greatly shorten the process of solving problems. Here’s an example. Example 1 As shown in Fig. 1, it is known that the point O is the symmetrical center of the parallelogram ABCD. EF and GH pass through the points O and EF, respectively, at AB and CD at points E, F and GH