【初中数学】一道课本上的作业题，改编成为八道中考数学难题

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                        第一课室                     
                     
                   


                   





               

               
               
               
               
                                               
                                                               
               
               

                   

                   

                   
                   
                   

圆为背景的相似三角形

证明圆中线段比例式（或多积式）是初中平面几何的重点知识．运用相似三角形去证明是最常见的方法，也是近几年来各省市中考命题的重点和热点．下面介绍运用相似三角报证明圆中线段比例式或等积式的基本思路。