To provide a method of creating a corner angle of a polyhedral structure which realizes simplification, easy machining, high material efficiency, and unskilled working, and also to provide a polyhedral structure having superior area efficiency and high designing performance.

A member having a vertical cross-section of point symmetry is cut with a cut angle A and a cut angle B satisfying following formulas, when angles between two faces kept into contact with each other, of a desired polyhedral structure are defined by a plane angle Y and an oblique angle V, and the cut faces are relatively rotated by 180 degrees and joined; tanA= cosV(90-Y/2)...(1), tanB=sinV(90-Y/2)...(2).