将三角形的边、角称为元素,已知三角形的若干元素(不少于三个,且至少有一条边),求其它元素的问题称为解三角形.解三角形的重要工具是锐角三角函数定义,正、余弦定理.如何根据条件选择定理、公式,需要对定理、公式的应用范围及题目的条件有深刻的理解,值得细细品味. The edges and corners of a triangle are called elements, and the elements of a triangle are known (not less than three and at least one edge). The problem of finding other elements is called solving triangles. The important tool for solving triangles is the definition of acute angle trigonometric functions. , Positive and cosine theorem. How to choose the theorem and formula according to the conditions, you need to have a deep understanding of the theorem, the scope of application of the formula and the conditions of the subject, it is worth savoring.