一、有效设问与置疑,引发学生有条理的思考教学《三角形边的关系》时,教师设计练习:有两根小棒,长度分别是5厘米与9厘米,再搭配上一根多长的小棒就一定能首尾相连围成一个三角形。(教师利用几何画板软件制作了一个可以拉动的三角形,其中两条边的长度分别是5厘米与9厘米,第三条边可以随着顶点的拉动不断变化它的长度)师:先想象,第三边能不能 First, the effective questioning and questioning, triggering students to think structured teaching “triangle side of the relationship,” the teacher design exercises: There are two small sticks, the length is 5 cm and 9 cm, and then with a long Small stick will be able to end to end surrounded by a triangle. (The teacher made a drawable triangle using geometric drawing software, where the lengths of the two sides are 5 cm and 9 cm, respectively, and the third side can change its length as the vertices pull.) Teacher: Imagine, Three sides can not