Face Area Node
The Face Area node outputs the surface area of a mesh's faces. The units are in Blender units no matter the unit system, equivalent to meters-squared at the default unit scale.
For quads and N-gons, when the face's vertices are not planar, the output is not necessarily the same as the sum of every one of the face's triangles visible in the viewport. In this case it should only be used an approximation. In some cases, the Triangulate Node can be used to get an exact value.
The surface area of each of the mesh's faces.
Combined with the Attribute Statistic(属性統計)ノード, this node can be used to calculate the total surface area of a mesh.