Calculation of Curved Surface Area Total Surface Area and Volume of Hemisphere

Public Class Form1

    Dim r, csa, tsa, vol As Single
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

    End Sub

    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        Const PI As Single = 3.142
        r = TextBox1.Text
        csa = 2 * PI * r * r
        tsa = 3 * PI * r * r
        vol = (2 * PI * r * r * r) / 3
        TextBox2.Text = csa
        TextBox3.Text = tsa
        TextBox4.Text = vol

    End Sub
End Class