近年来锐角三角函数求值问题是中考的常见题型,锐角三角函数与前面所学的“一次函数、二次函数和反比例函数”不同,它的自变量是锐角,函数值是直角三角形中边的比值,所以找直角三角形是解决这类问题的关键,也是学生实际解题时的难点,下面就以不同的问题背景为例,总结构造直角三角形的方法,进而优化解题策略.一、作垂直构造直角三角形 In recent years, the acute trigonometry trigonometric function problem is a common problem in the senior high school entrance examination, acute trigonometric functions and previously learned “primary function, quadratic function and inverse function”, its argument is acute angle, the function value is a right triangle Therefore, finding the right triangle is the key to solving this kind of problem and also the difficulty when students actually solve the problem. The following is a summary of the method of constructing a right-angle triangle, and then to optimize the problem-solving strategy. , Vertical structure for the right triangle