应该怎样分类

• 作 者: 杏园
• 出 处: 安徽教育
• 发表日期: 1988年03期
• 关键词: 不等边三角形 划分原则 分类标准 于集 小学教师 立角

在教学第七册《三角形、平行四边形和梯形》的时候，纤常听到有的老师作这样的分类：“三角形按边分类，可以分成不等边三角形、等腰三角形和等边三角形三种；梯形可分为一般梯形、等腰梯形和直角梯形三种。”这是与概念的划分原则是相背的。要知道，概念的划分原则归纳起来有四条，即要有一个分类的统一标准；划分时要做到“不遗

When teaching the seventh book “Triangles, Parallelograms, and Trapezoids”, Filipino often heard some teachers make this classification: “Triangles are categorized by edge and can be divided into inequality triangles, isosceles triangles, and equilateral triangles. Trapezoidal can be divided into three types: general trapezoid, isosceles trapezoid and right-angle trapezoid. This is contrary to the concept of the concept of division. It should be noted that the principle of dividing the concept is summed up in four, that is, there must be a uniform standard of classification;