《中小学数学》(初中版)2015年1、2期合刊上刊登了陈菊的《关于一个几何命题的否定及完善》一文,文中呈现了一位教师围绕学生提出的问题而展开的探究历程.阅后被陈老师的孜孜以求的精神所感染.陈老师在文中的问题完善部分提出了两个命题,并且利用海伦公式、余弦定理等知识给出了漂亮的代数证明,证明过程中的巧妙的设元及代数式的变形让人深 “Primary and secondary mathematics” (junior high school version) 2015 1, 2 period issue of the publication of Chen Ju’s “On a geometric proposition of the negative and perfect,” a text presented in the text of a teacher around the students raised the issue of inquiry Course.After being read by Chen’s diligently sought-after spirit.Chen teacher put forward two propositions in the problem of the perfect part of the article, and use the Helen formula, cosine theorem and other knowledge to give a beautiful algebra to prove that the process of clever The set of yuan and algebraic deformation makes people deep