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多面体的截面作图主要依据平面基本性质(两个公理)与确定平面的基本条件(一个公理及三个推论)。多面体的计算要抓好定位、定形、定量三个主要环节,首先由上述思想方法确定关键点,由关键点确定截面与多面体有关的交线,其次根据题目已知条件与空间点、线、面的关系确定截面(一般为多边形)的基本特征,然后熟练运用平面几何图形的有关性质
The cross-section of the polyhedron is mainly based on the basic properties of the plane (two axioms) and the basic conditions for determining the plane (one axiom and three corollaries). The calculation of polyhedrons should focus on three main links: positioning, shaping, and quantification. First, the key points are determined by the above-mentioned thinking methods, and the cross-sections related to the polyhedrons are determined from the key points, followed by the known conditions and space points, lines, and planes. The relationship determines the basic characteristics of the section (usually a polygon), and then uses the relevant properties of the plane geometry