向量是数学新教材的重要概念之一 ,由于向量能有效地将复杂的几何论证问题转化为简单的数学运算 ,体现了中学数学重要的思想方法之一———转化思想 .向量方法在平面几何、立体几何及解析几何中有广泛的应用 ,其在新教材中占有较重的份量 .现举例说明向量的数量积在几何中的应 Vector is one of the important concepts of new mathematics textbooks. Because vector can effectively transform complex geometric argumentation problems into simple mathematical operations, it embodies one of the important thoughts and methods of middle school mathematics—transformation. The vector method is in plane geometry. There is a wide range of applications in stereo geometry and analytic geometry, which occupies heavier weight in new textbooks. Here is an example of how the number product of vectors should be in geometry.