一、类比联想。平几不少证题方法,可“类似地”用于立几中,如“求证平行六面体四条对角线交于一点且各自被此点平分”,可用平几中证若干条直线共点的方法:先证其中两条交于O,再证其他也过O,就行了。又如证空间四边形有关题可类比于平面四边形考虑,受“面积证题术”启发,可用 First, analogy. Many test methods can be used to “stand similarly” to establish a few, such as “to verify that four parallel lines of hexahedron intersect at one point and are equally divided by this point”. Several lines can be used to share the same points. Method: First prove that two of them are handed over to O, and then the other is also O, and that’s all. Another example is that the questions related to the space quadrangle can be considered analogous to the planar quadrilateral, and inspired by the “area stamping technique”.