запуталась с Else

Private Sub Command1_Click()
Dim a, b, c As Double
Picture1.Cls
a = Val(Text1)
b = Val(Text2)
c = Val(Text3)
If (a > 0) And (b > 0) And (c > 0) And (a + b > c) And (a + c > b) And (b + c > a) Then 
   Picture1.Print "треугольник существует"
   If (Sqr(a) + Sqr(b) >= Sqr(c)) And (Sqr(a) + Sqr(c) > Sqr(b)) And (Sqr(b) + Sqr(c) > Sqr(a)) Then 
      Picture1.Print "треугольник остроугольный" 
   Else 
      Picture1.Print "треугольник не остроугольный"
   EndIf
Else 
   Picture1.Print "треугольник не существует"
EndIf
End Sub

Private Sub txt_TextChanged(ByVal sender As TextBox, ByVal e As System.EventArgs) Handles txtA.TextChanged, txtB.TextChanged, txtC.TextChanged
        Dim temp As Single
        If sender.TextLength = 0 Then Exit Sub
        If Not Single.TryParse(sender.Text, temp) Then
            MsgBox("Необходимо вводить число!", MsgBoxStyle.Exclamation)
            If sender.TextLength > 0 Then
                sender.Text = sender.Text.Remove(sender.TextLength - 1, 1)
                sender.SelectionLength = 0
                sender.SelectionStart = sender.TextLength
            End If
        End If
        temp = Nothing
    End Sub
 
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Dim a, b, c As Single
        Me.lblResult.Text = String.Empty
        Try
            a = CSng(txtA.Text)
            b = CSng(txtB.Text)
            c = CSng(txtC.Text)
        Catch ex As Exception
            MsgBox(ex.Message, MsgBoxStyle.Exclamation)
        End Try
        Select Case Me.IsPossibleTriangle(a, b, c).ToString
            Case Is = False
                Me.lblResult.Text = "Невозможно построить треугольник!"
            Case Is = True
                Me.lblResult.Text = "Отрезки могут составлять треугольник: " & Me.GetRectangleType(a, b, c)
        End Select
    End Sub
 
    Private Function IsPossibleTriangle(ByVal a As Single, ByVal b As Single, ByVal c As Single) As Boolean
        If (a < (b + c)) And (b < (a + c)) And (c < (a + b)) Then Return True
        Return False
    End Function
 
    Private Function GetRectangleType(ByVal a As Single, ByVal b As Single, ByVal c As Single) As String
        Dim alpha, beta, gamma As Single
        alpha = Math.Acos((b ^ 2 + c ^ 2 - a ^ 2) / (2 * b * c)) * 180 / Math.PI
        beta = Math.Acos((a ^ 2 + c ^ 2 - b ^ 2) / (2 * a * c)) * 180 / Math.PI
        gamma = 180 - alpha - beta
        If (alpha < 90) And (beta < 90) And (gamma < 90) Then Return "остроугольный"
        If (alpha = 90) Or (beta = 90) Or (gamma = 90) Then Return "прямоугольный"
        Return "тупоугольный"
    End Function