Вывод в listbox - VB

Public Structure treugolniki
        Dim a, b, c As Single
        Dim p As Single
        Public Sub vvod()
            Dim a, b, c As Single
            a = Val(InputBox("VVedite 1 storonu treugolnika"))
            b = Val(InputBox("VVedite 2 storonu treugolnika"))
            c = Val(InputBox("VVedite 3 storonu treugolnika"))
        End Sub
        Public Function perimetr() As Single
            Dim p As Single
            p = a + b + c
            perimetr = p
        End Function
        Public Function stroka_dlya_vuvoda() As String
            Dim s As String
            s = "1,2,3 storonu treugolnika sootvetstvenno: " + Str(a) + " " + Str(b) + " " + Str(c) + ".Perimetr: " + Str(perimetr)
            stroka_dlya_vuvoda = s
        End Function
    End Structure
    Public Sub vvod_massiva_treugolnikov(ByRef X() As treugolniki, ByVal n As Integer)
        n = Val(InputBox("Vvedite kolichestvo treugolnikov"))
        ReDim X(n - 1)
        For i = 0 To n - 1
            X(i).vvod()
            X(i).perimetr()
        Next
    End Sub
    Public Sub vuvod_massiva(ByRef list As ListBox, ByVal x() As treugolniki, ByVal n As Integer)
        Dim i As Integer
        ListBox1.Items.Clear()
        For i = 0 To n - 1
            list.Items.Add(x(i).stroka_dlya_vuvoda)
 
        Next
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim x() As treugolniki
        Dim n As Integer
        vvod_massiva_treugolnikov(x, n)
        vuvod_massiva(ListBox1, x, n)
 
    End Sub
End Class