要折叠一个无盖的正方体纸盒,如图1,关键是能画出一个无盖的正方体纸盒的平面展开图.图1图2同学们大都熟悉这样一种操作:把一个正方形纸片平均分成9个小正方形,拿去四个角的4个小正方形就得到图2.用图2这5个相连的正方形就可以折叠成图1这个无盖的正方体盒子.图1中的5个面的名 To fold a square box without a lid, as shown in Figure 1, the key is to draw a plane unfolded image of a box without a lid. Figure 1 Figure 2 Most of the students are familiar with this kind of operation: the average of a square piece of paper Divided into 9 small squares, take the 4 small squares of the four corners to get Figure 2. Using the 5 connected squares of Figure 2 can be folded into a box-shaped box without lid. The 5 faces in Figure 1 The name