平面直角坐标系是研究数形结合问题的最好工具,根据坐标平面内顶点的坐标求图形面积,很好地体现了几何问题的代数解法.下面就举例说明如何利用平面直角坐标系来求图形的面积,希望对同学们有所启示.一、坐标平面内三角形面积的求法1.有一边在坐标轴上或平行于坐标轴例1如图1,平 The plane rectangular coordinate system is the best tool for studying the combination of number and shape. The area of ​​the graph is calculated according to the coordinates of the vertices in the coordinate plane, which is a good example of the algebraic solution of the geometric problem. The following example illustrates how to use the plane rectangular coordinate system to find the figure. The area, I hope to have some enlightenment to the students. First, the method of the triangle area in the coordinate plane 1. There is a side on the coordinate axis or parallel to the coordinate axis Example 1 Figure 1, flat