构造法是数学中一种富有创造性的思维方法,常常通过分析问题的结构特征和内在规律,经过概括抽象,构造出一个与原问题密切相关的等价或可弥补的非等价的数学模型,并希望通过对所构造模型的处理,实现转化,使问题获解.有些三角问题,若用常规方法求解,往往运算繁琐,一筹莫展.但我们如果能巧妙地构造某些模型,往往能化繁为简,化难为易,现举数例.供同学们参考. Constructive method is a kind of creative thinking method in mathematics. It often analyzes the structural features and internal laws of the problem, and after summarizing and abstracting, constructs an equivalent or reparable non-equivalent mathematical model closely related to the original problem. It is hoped that through the processing of the constructed model, the transformation will be achieved and the problem will be solved. Some trigonometric problems, if solved by conventional methods, are often cumbersome and unsuccessful. However, if we can skillfully construct certain models, they can often become confusing. Simple, difficult to change, give a few examples. For students to reference.