以运动的观点发现数学定理间的联系, 在运动中观察几何元素之间的关系,分析过程,强化思维,这在运用多媒体的过程中,确实能起到化难为易,举一反三的功效. 例1 图1所示是相交弦定理的基本图形,两条直线的交点P在圆内.通过多媒体课件作如下展示:把交点P移到圆外,如图2 From the viewpoint of sports, we can find the connection between mathematical theorems, observe the relations among geometric elements in the movement, analyze the process, and strengthen the thinking. In the process of using multimedia, this can really make it difficult to understand, and it can be used as an example. Figure 1 shows the basic graph of the intersecting string theorem. The intersecting point P of the two straight lines is in the circle. The multimedia courseware makes the following display: Move the intersection point P to the circle, as shown in Figure 2.