1.本单元知识的重点、难点分析本单元的重点是正弦定理和余弦定理,这两个定理将三角形的边、角关系以公式的形式给出来了,应注意公式的推导、理解、变形形式与灵活应用,能够运用解斜三角形知识求解实际应用问题.本单元的难点是灵活运用正弦定理、余弦定理解斜三角形.学习本单元 1. The unit of knowledge of the key and difficult points of analysis The focus of this unit is the sine and cosine theorem, the two theorems will be the triangle side of the angle to the formula given in the form, we should pay attention to formula derivation, understanding, deformation And flexible application, can solve the practical application problem by using the knowledge of solution triangle.The difficulty of this element is to flexibly use the sine theory and the cosine theorem to solve the oblique triangle.