正方体是立体几何中的基本的几何体.由于它结构对称.各元素之间有相等、平行、垂直等特殊关系.因此,各届“希望杯”赛题,都从不同的侧面对其进行了考查.通过研究这些问题,同学们的立体几何水平一定大有提高. The cube is the basic geometry in the three-dimensional geometry. Because of its structural symmetry, there are special relations such as equal, parallel and vertical between each element. Therefore, each session of the “Hope Cup” game has been examined from different sides. By studying these problems, the students’ three-dimensional geometric levels must be greatly improved.