所谓构造“几何图形”是指在解决某个问题时,根据所解问题的内部联系、数量特征,找出相应的几何图形。“构造”得好,解题就变得非常简洁,直观明了。如果问题条件中有明显的或隐含的几何意义与背景,或能以某种方式与几何图形建立起联系,则可考虑构造几何图形,将题设中的数量关系直接在图形中得以实现。然后,借助于图形的性质在所构造的图形中寻求问题的结论。 The so-called structure “geometry ” refers to the solution of a problem, according to the internal problems of the solution, the number of features, find the corresponding geometry. “Construction ” Well, the solution becomes very simple, intuitive and clear. If there are obvious or implicit geometric meanings and backgrounds in the condition of the problem, or if the problem can be related to the geometry in some way, we can consider constructing the geometry and implementing the relationship of quantity in the problem directly in the graph. Then, with the help of the nature of the graph, we seek the conclusion of the problem in the constructed graph.