《中小学数学》(初中版)2009年第5期刊出了罗权的《也谈关于平行四边形反例的存在性》,他给出了利用平行四边形寻找“有一组对边相等,一组对角相等的四边形是平行四边形”的反例所具备的条件:①在平行四边形中,已知相等的一对边必须是满足两邻边与对角线所围成的三角形中的最大边;②在平行四边形中,两邻边与对角线所围成的三角形中的最大角α的取 “Elementary and middle school mathematics” (junior high school edition) 2009 fifth issue of Luo Quan’s “about the existence of parallelogram inverse counterexample”, he gives the use of parallelogram to find “there is a pair of equal-edge, a pair of Equivalent quadrilateral is parallelogram ”counterexample have the following conditions: ① In the parallelogram, the same side of an edge must be satisfied to meet the two sides of the triangle and the diagonal surrounded by the largest edge; ② In a parallelogram, the two sides of the triangle surrounded by the diagonal and the largest angle α to take