判定三角形形状，通常按如下的步骤进行：1．先用已学过的知识将题目给定的已知条件转化为只含有边或只含有角的等量关系式；2．将变形后的等量关系式进行化简3．根据化街结果用有关的定义、性质、定理等判定．从上面可以看出，适当地选用转化和化问方法是获得巧解的重要一环， To determine the shape of the triangle, usually follow the following steps: 1. First use the knowledge that has been learned to convert the known conditions given by the topic into an equal-valued relation that contains only edges or only corners; Simplify the transformed equivalent equations. According to the results of the street, we use the relevant definitions, properties, theorems, etc. As can be seen from the above, the proper selection of transformation and transformation methods is an important part of achieving sensible solutions.