在近年的中考试题中,常见这样一类问题:在给定的已知条件下,让考生先证明一个结论;然后改变原题中的某个已知条件,让考生探索原来的结论是否仍然成立,或者探索一个与原结论类似的结论是否成立.求解此类问题的思路是:仔细分析条件变化前与条件变化后图形的特点,比较其差异,再确定要判断的结论与哪些因素有关,变中求同,以不变应万变.1.已知条件改变,解法步骤依旧 In recent years, the middle school exam questions, such a common problem: given given conditions, let the candidates to prove a conclusion; then change the original title of a known condition, so that the candidates to explore the original conclusion is still true , Or to explore whether a similar conclusion with the original conclusion is established.The idea of ​​solving such problems is: careful analysis of changes in conditions before and after changes in the characteristics of the graphics, compare the differences, and then determine the conclusions to be judged with what factors, In the same, with the same .1. Known conditions change, solution method still