一、创设游戏情境,引入新课师:喜欢做游戏吗?好,我们来玩一个比一比,看谁又好又快地围成一个三角形。哪两位同学来试一试?我们知道由三条线段围成的图形叫三角形。如果用小棒代替线段围三角形,得用几根小棒?(3根)我们来当好公正的裁判员,好不 First, the creation of the game situation, the introduction of a new class teacher: Do you like to play games? Well, let’s play a ratio, to see who is good and quickly surrounded by a triangle. Which two students to try? We know that the figure surrounded by three lines called triangles. If you replace the line with a small rod around the triangle, you have to use a few small stick? (3) We have to be a fair referee, so good