近期,笔者从国外中学数学教材上看到一个图形,如图1所示.对于图中每个多边形的面积,感觉很有意味,尝试研究一下.我们把这个图形用确切的数学语言表达出来:如图2,D,E,F,G,H,I分别为△ABC的边BC,CA,AB的三等分点,连接△ABC的顶点与对应的三等分点,把△ABC分成12个三角形、3个四边形、3个五边形和1个六边形,共19个多 Recently, the author has seen a graph from the mathematics textbooks for secondary schools abroad, as shown in Figure 1. For each polygon area in the graph, it feels very interesting. Try to study it. We express this graph in the exact mathematical language: As shown in Fig. 2, D, E, F, G, H, and I are the three-division points of the sides BC, CA, and AB of △ABC, respectively, connecting the vertexes of △ABC and the corresponding trisection points, and dividing ΔABC into 12 Three triangles, three quadrilaterals, three pentagons, and one hexagon, a total of 19