“构造法”是一种创造性很强的解题方法,是通过对问题的观察、分析,抓住特征,联想熟知的数学模型,然后变换命题,恰当地构造新的数学模型来达到解题目的的方法.构造法的突破是创新,即在解题时常常打破常规,另辟蹊径,表现出简洁、明快、精巧等特色;构造法的核心是构造,即通过构造合适的辅助元素,作为解决问题的桥梁,从而打开解题的通道,使问题得到解决.如果能巧妙地构造某些模型,往往能化繁为简,化难为易,使 Construction method is a highly creative solution to the problem, through the observation of the problem, analysis, seize the characteristics of the familiar mathematical model, and then transform the proposition, the proper construction of a new mathematical model to achieve the solution The breakthrough of construction method is innovation, that is to say, it often breaks the routine and opens a new path in solving problems, showing the characteristics of simplicity, bright and delicate, and so on; the core of construction method is construction, that is, constructing appropriate auxiliary elements as solutions Problem bridge, so as to open the channel for solving problems so that the problem can be solved.If we can cleverly construct some models,