Función Raíz Cuadrada

Public Class Form4
Dim a, b As Integer
Function raiz(ByVal a As Integer) As Integer
raiz = Math.Sqrt(a)
End Function

Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
a = TextBox1.Text
b = raiz(a)
Label3.Text = b
End Sub
End Class