解圆锥的组合问题时,有时难于想象它们在空间的位置.如果断定考察的圆锥在“构架”中(多面体的棱形成的图形),则简化了圆锥的空间的认识.这时问题的对象变得更加“显著”,并且解的途径简单而迅速,这对于学生来说特别重要.首先我们证明一个定理. When solving the problem of the combination of cones, it is sometimes difficult to imagine their position in space. If it is determined that the cone under consideration is in the “architecture” (a graphic formed by the edges of a polyhedron), the understanding of the conical space is simplified. At this time, the object of the problem is changed. It is more “significant” and the solution is simple and rapid. This is especially important for students. First we prove a theorem.