实验教科书(北师大版)七年级上册的第一章是《丰富的图形世界》.在这一章中,教科书设置了“生活中的立体图形”、“展开与折叠”、“截一个几何体”、“从不同方向看”、“生活中的平面图形”五节内容.初拿教材,感到困惑与棘手.不明白教科书为何如此设置,平面图形还没有学习,就 The first chapter of the seventh grade of the experimental textbook (Beijing Normal University Edition) is “The Rich Graphical World.” In this chapter, the textbook sets “three-dimensional graphics in life”, “expanding and folding”, and “cutting a geometry”. ”,” “View from different directions”, “Flat graphics in life” Five sections. Getting textbooks, feel puzzled and thorny. Do not understand why textbooks are so set, flat graphics have not yet learned,