近年来,各地中考中频频出现一类问题,需要通过添加辅助圆求解,即利用圆的有关性质,建立起条件和结论之间的联系,从而化隐为显,找到解题的切入点.下面举例说明辅助圆的作法.一、利用“直径所对的圆周角是直角”构造辅助圆例1(2012年广州中考题)如图1,抛物 In recent years, a series of problems have frequently occurred in local examinations. It is necessary to solve them by adding auxiliary circles, that is, to use the relevant properties of circles to establish the connection between conditions and conclusions, so that the connection between the conditions and conclusions is obvious, and the entry point for solving problems is found. An example to illustrate the practice of the auxiliary circle. First, the use of “ diameter of the circle angle is right angle ” construction auxiliary circle example 1 (2012 Guangzhou exam questions) Figure 1, parabolic