Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim i As Integer = InputBox("")
        Dim j As Integer = InputBox("")
        Dim k As Integer = InputBox("")
        MsgBox(area1(i))
        MsgBox(area1(j, i))
        MsgBox(area1(k, j, i))
    End Sub
    Function area1(ByVal a As Integer)
        Dim ans As Single
        ans = Math.PI * (Math.Pow(a, 2))
        Return ans
    End Function
    Function area1(ByVal a As Integer, ByVal b As Integer)
        Dim ans As Integer
        ans = a * b
        Return ans
    End Function
    Function area1(ByVal a As Integer, ByVal b As Integer, ByVal c As Integer)
        Dim ans As Single
        ans = ((c + b) * a) / 2
        Return ans
    End Function

    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        Dim i As Integer = InputBox("")
        MsgBox(power(2, i))
    End Sub
    Function power(ByVal a As Integer, ByVal b As Integer)
        Dim ans As String = "1"
        Dim j As Integer
        For j = 1 To b
            ans = ans & "+ " & a & "^" & j
        Next
        Return ans
    End Function