平面与空间的转化，变与不变的升华--立体几何翻折问题探究

摘要

The folding problem, as an important problem in solid geometry, is the concentrated embodiment of the transformation between plane geometry and spatial geometry. In the inquiry into the folding problem, the relationship between variability and in-variability should be fully utilized, and the changeless geometri-cal volume and positional relationship on the same side of the fold line before and after the folding should be grasped.%翻折问题是立体几何的重要问题，是平面几何与空间几何问题转化的集中体现。翻折问题的探究必须充分利用不变量和不变关系，抓住翻折前后始终位于折线同侧的几何量和位置关系保持不变。