Parametro non valido

Dim pX AsInteger = CInt(ImmMain.Width / 2)

Dim pY AsInteger = CInt(ImmMain.Height / 2)

Dim grpath As GraphicsPath = Poligono(CSng(50),CSng(6), CSng(pX), _

                                      CSng(pY), CSng(0))

ImmMain.CreateGraphics.DrawPath(RitPen, grpath)

errore generato parametro non valido , a me i parametri passati sembrano corretti ma sta di fatto che VB2008 non ne vuole sapere e non capisco il perché.

Grazie anticipate se qualcuno è in grado di aiutarmi

   PublicSharedFunction Poligono(ByVal lato AsSingle,ByVal NLati _

                                   AsSingle, ByVal Xc AsSingle, _

                                   ByVal Yc AsSingle, ByVal GrRotaz _

                                    AsSingle) As GraphicsPath

        Using GrP AsNew GraphicsPath

            Dim Arc(CInt(NLati))AsSingle

            Dim vertX(CInt(NLati))AsSingle

            Dim vertY(CInt(NLati))AsSingle

            Dim RdRotaz AsSingle = CSng(GrRotaz * Math.PI / 180)

            Dim ARCHI AsSingle = CSng(360 * Math.PI / 180 / NLati)

          Dim NFisso AsSingle = CSng(0.5 / Math.Tan(Math.PI / NLati))

            Dim Apotema AsSingle = NFisso * lato

            Dim Raggio AsSingle = CSng(Math.Sqrt(Apotema ^ 2 + _

                                                 (lato / 2) ^ 2))

            For k AsShort = 0 ToCShort(NLati)

                Arc(CInt(k)) = ARCHI * k

            Next

            For k AsShort = 0 ToCShort(NLati - 1)

             vertX(k) = CSng(Xc + Raggio * Math.Sin(Arc(k) + RdRotaz))

             vertY(k) = CSng(Yc - Raggio * Math.Cos(Arc(k) + RdRotaz))

          'GrP.AddLine(vertX(k), vertY(k), vertX(k + 1), vertY(k + 1))

            Next

            For k AsShort = 0 ToCShort(NLati - 2)

           GrP.AddLine(vertX(k), vertY(k), vertX(k + 1), vertY(k + 1))

            Next (k)

           GrP.CloseFigure()

            Return GrP

        EndUsing

    EndFunction