Different heuristic approaches, such as physical optics method, method of equivalent edge currents and modyfied method of equivalent edge currents [1] are exemplified in a problem of electromagnetic scattering by a plane angular sector.

Comparing with rigorous results [2] has shown that for the problem of electromagnetic diffraction by polyhedrons physical optics method can lead to serious mistakes, method of equivalent edge currents gives a qualitatively correct solution and modified solution by equivalent edge currents method is the most close to a rigorous one.