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近几年,把“能从较复杂的图形中分解出基本的图形,并能分析其本图形中的基本元素及其关系,利用直观来进行思考”纳入了数学教学的课标要求,因此各地的中考试题中经常会出现各种基本图形的变形.所以初中平时的数学教学如能抓住一些基本图形的话,学生在中考中势必能得心应手.“K”型图就是其中的一种基本图形.下面以近几年各地中考试题中出现的这种基本图形为例,阐述它在数学解题中的应用.一、“K”型图的基本模型如图1,AB⊥BD于点B,CD⊥BD于
In recent years, “” can be decomposed from the more complex graphics of the basic graphics, and can analyze the basic elements of the graphics and their relationships, the use of intuitive thinking “into the mathematics teaching standard requirements, Therefore, all over the exam questions often appear in a variety of basic graphics deformation.So junior high school mathematics teaching usually seize some of the basic graphics, students will certainly be handy in the test. ”K “ type map is one of them Kind of basic graphics below in recent years around the examination questions in the basic graphics as an example, explain its application in mathematical problems. First, ”K " type diagram of the basic model shown in Figure 1, AB ⊥ BD At point B, CD⊥BD at