大家知道,三角形形状可以用几何方法从它的边或角的大小来进行判定。用三角法判定三角形形状,应根据题型,灵活运用三角公式,若条件复杂,还必须结合代数和几何知识,使问题由隐晦变为明显,化难为易。常用的方法有: As we all know, the shape of a triangle can be determined geometrically from the size of its edge or corner. Triangular method to determine the shape of the triangle should be based on the type of question, the use of trigonometric formulas, if the conditions are complex, we must also combine the knowledge of algebra and geometry, so that the problem becomes obvious from the concealment, difficult to change. Common methods are: