在“平行四边形”这一单元的教学中 ,重点是平行四边形的概念、性质、判定。难点是平行四边形和各种特殊平行四边形之间的区别和联系。因为它们的概念之间重叠交错、容易混淆 ,学生往往搞不清它们的共性、特性及其从属关系。为此 ,教学中在讲清概念类征的同时要强调它们的种概 In the teaching of the “parallelogram” unit, the emphasis is on the concept, nature, and judgment of parallelograms. The difficulty is the difference and connection between parallelograms and various special parallelograms. Because their concepts are overlapping and confusing, students often cannot understand their commonalities, characteristics, and affiliations. To this end, in teaching, while clarifying the concept of symptoms, they must emphasize their species.