OOP VOLUME KUBUS YANG DIDALAM NYA ADA TABUNG Dengan VB Net

Public Class Form1

    Public Class tabung
        Public Tinggi As Single
        Public jari_jari As Single
        Const phi = 3.14

        Public Function Volume_tabung() As Double
            Return phi * jari_jari * jari_jari * Tinggi
        End Function
    End Class

    Public Class kubus
        Public Rusuk As Single
        Public Function Volume_kubus() As Double
            Return Rusuk * Rusuk * Rusuk
        End Function
    End Class



    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim objtabung As New tabung
        With objtabung
            .Tinggi = TextBox1.Text
            .jari_jari = TextBox2.Text
            TextBox3.Text = .Volume_tabung
        End With

        Dim objkubus As New kubus
        With objkubus
            .Rusuk = TextBox4.Text
            TextBox5.Text = .Volume_kubus
        End With
        TextBox6.Text = TextBox5.Text - TextBox3.Text
    End Sub
End Class