“凡事预则立,不预则废”.教师认真而充分的备课,是保证教学顺利进行的首要环节.如果能在此基础上实施创新、精心设计,将会演绎出更为精彩的课堂,促成数学课堂高效达成.本文拟就本人执教的《全等三角形的判定(2)——SAS公理》某个教学环节谈谈自己的一些想法和做法,供同行参考. “The precondition of all legislation, not prejudice. ” The teacher’s careful and full preparation lesson, is to ensure the smooth progress of teaching the first step.If this can be implemented on the basis of innovation, well-designed, will deduce a more exciting Classroom, to facilitate the efficient completion of the mathematics classroom.This article intends to teach my own “adjudgement triangle (2) - SAS axioms” some of the teaching to talk about some of their own ideas and practices for peer reference.