图形是“数”的几何表现,可以使许多抽象概念和数量关系直观化、形象化、简单化.向量是既有大小又有方向的量,是沟通“数”与“形”的重要工具,是代数、几何之间的桥梁.所以,在解向量题时,从图形的角度考虑问题,有时可使题目中的各种关系直观明白,便于问题解决.那么如何构造图形呢?本文分类例说如下.一、构造点例1如图1,平行四边形ABCD中,E,F分别是BC、DC的中点,G为DE与BF的交点, Graphs are geometric representations of numbers that allow many abstract concepts and quantities to be visualized, visualized, and simplified, and vectors are quantities of both size and direction, ", Is an important tool of algebra and geometry, so when we solve the vector question, we can consider the question from the angle of the figure, sometimes we can understand the various relations in the title and make it easier to solve the problem. First, the construction point Example 1 As shown in Figure 1, parallelogram ABCD, E, F are the midpoints of BC, DC, G is the intersection of DE and BF,