解直角三角形是三角学内容的重要部分,这一部分的重点是锐角三角函数的概念和直角三角形的解法.特殊锐角与其三角函数之间的对应关系也很重要,应当牢记.三角函数定义是本章的第一个重点,因为它是全章乃至全部三角学的预备知识.有了锐角三角函数的概念,解直角三角形,引入任意角 Solving right triangles is an important part of trigonometry. The focus of this section is the concept of acute angle trigonometric functions and the solution of right angle triangles. The correspondence between special acute angles and their trigonometric functions is also important and should be kept in mind. The definition of trigonometric functions is the subject of this chapter. The first point is because it is the preparatory knowledge of the whole chapter or even the entire trigonometry. With the concept of acute angle trigonometric functions, solve the right triangle, introduce an arbitrary angle