A method for modeling a triangle meshed interconnect structure using an electrically equivalent three rectangle combination for each triangle in the triangle mesh is described. In the method, a surface of an interconnect structure is meshed with triangles. Three rectangles are then defined for each triangle so that each rectangle shares a different side of the triangle. Rectangle circuit models are determined so that the three rectangles are approximately equivalent electrically to the triangle when coupled together. The interconnect circuit model is then formed by connecting together the rectangle circuit models for all triangles defined on the surface of the interconnect structure.