同学们，见过蜂窝吗？蜂窝的横断面是正大边形，但蜂房并非正六棱柱，房底由三个全等菱形拼成．蜂房的这种结构引出了一个有趣的故事．经过计算我们可以知道，周长一定的图形中圆的面积最大，然而圆是不能铺满平面的，而能铺满平面的正多边形只有正三角形、正方形和正六边形． Students, have you seen the honeycomb? The cross section of the honeycomb is a large square, but the hive is not a regular hexagonal prism, and the bottom of the cell is made up of three congruent diamonds. This structure of the hive leads to an interesting story. After calculation, we can know that the area of ​​the circle in the graph with a certain circumference is the largest, but the circle cannot be covered with a plane, but the regular polygons that can be covered with a plane are only the triangles, squares, and regular hexagons.