Calculate area of circle and use pi value as constant in VB.NET.

PROPERTIES:

Label1
Text	Area Of Circle is:0
TextBox1
Text	0

CODEING:

Public Class Form1
    Private Sub TextBox1_TextChanged(sender As Object, e As EventArgs) Handles TextBox1.TextChanged
        Label1.Text = "Area Of Circle is :" & Math.Round((22 / 7) * (Val(TextBox1.Text) ^ 2), 2)
    End Sub
End Class

DESIGNING: