论文部分内容阅读
类比三角形中位线的定义,我们规定:连接平面或空间四边形对边中点的线段叫做四边形的中位线.本文首先给出任意四边形中位线一个优美的向量性质,并由此得到四边形两条中位线与边长的等量关系;然后据此得出一种求异面直线间夹角的计算方法,以及给定四边形四边长时其面积最大值的计算公式;最后笔者结合四道实例说明这些性质在数学中的应用,权当抛砖引玉.1.四边形中位线的性质性质1在任意四边形ABCD中,E,F分别是
In the definition of bit lines in analogy triangles, we define that the line connecting the midpoint of the quadrilateral of the plane or space is called the median line of the quadrilateral. In this paper, we first give a graceful vector property of the bit lines in any quadrilateral, And then the equivalent relationship between the bit line and the side length; and then derived a method of calculating the included angle between different surface straight lines, and given a quadrilateral long side of the maximum area when the formula; Finally, the author combined with four Examples illustrate the application of these properties in mathematics and should be given priority when discussing the following aspects.1 The nature of bit lines in quadrilaterals 1 In any quadrilateral ABCD, E and F are