单元坐标法求截面静矩、惯性矩及惯性积

Using the Unit of Coordinate to find Moment of Area， the Moment of Inertia and The Product of Inertia

一种利用三角形单元顶点坐标来求静矩、惯性矩、惯性积的方法，可用于求复杂形状截面的静矩、惯性矩及惯性积．

：The unit of coordinate of the vertex on the triangle can find the moment of area， moment of inertia and the product of inertia on the cross－section， by which the problems on the cross－section of complex shape can also be solved．