给出平面上多边形的面积矢量的定义及公式，并应用它求出多边形的面积公式。
Give a definition about area vector of a polygon on the plane and its formula, area formula of a polygon can be sought by it.
我们证明，当边长已知的多边形的面积达到最大时，该多边形的顶点一定共圆。
We also show that when the maximal area of such a polytope is attained, the vertices of it are just co-circular.
在用容积法计算地质储量的过程中，含油面积的确定实际上是计算多边形的面积。
In the process of reserve calculation using volumetric method, to confirm oil-bearing area is in fact to calculate polygon area.
应用推荐