课程改革实施以来,如何提高课堂教学的有效性,是数学教学的热点问题.下面以一堂专题复习课《全等三角形与轴对称》为例,说明以题组变式教学提升学生思维能力的做法与体会.原题(人教版八年级)如图1,已知等腰ABC中,点D为底边BC上的中点,DE⊥AB Since the implementation of the curriculum reform, how to improve the effectiveness of classroom teaching is a hot issue in mathematics teaching.With a special review class “congruent triangles and axisymmetric” as an example, And experience. The original title (PEP eighth grade) as shown in Figure 1, known isosceles ABC, D is the midpoint of the base BC, DE⊥AB