不少学生对我讲学习几何的困难,有些题明知要添辅助线,就是不知道怎样去添加.例如:如图1,已知六边形ABCDEF,它的六个内角都是120°,且AB=1,BC=3,CD=3,DE=2,求这个六边形的周长.图1几何学习中添辅助线确定是学习上的难点,然而它又能活跃思维,激发对学习的兴趣.其实辅助线是客观 Many students told me about the difficulty of learning geometry. Some of the questions clearly knew that we had to add an auxiliary line. We didn’t know how to add it. For example: As shown in Figure 1, the hexagon ABCDEF is known, its six internal angles are 120°, and AB=1, BC=3, CD=3, DE=2, find the perimeter of this hexagon. Figure 1 Adding auxiliary lines in geometry learning is difficult to learn, but it can also be active thinking and stimulate learning Interest. In fact, the auxiliary line is objective