Public Class Form1
    Dim pList As New List(Of PointF)
       Private Sub Form1_Paint(ByVal sender As Object, ByVal e As _
         System.Windows.Forms.PaintEventArgs) Handles Me.Paint
        e.Graphics.SmoothingMode = Drawing2D.SmoothingMode.HighQuality
        For Each p As PointF In pList
            e.Graphics.FillEllipse(Brushes.Red, p.X, p.Y, 10, 10)
        Next
    End Sub
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles MyBase.Load
        TrackBar1.Maximum = 13
    End Sub
    Private Sub TrackBar1_Scroll_1(ByVal sender As System.Object, ByVal e As _
      System.EventArgs) Handles TrackBar1.Scroll
        Dim tw() As Int32 = {4, 5, 6, 8, 9, 10, 12, 15, 20, 24, 30, 40, 45, 60}
        pList.Clear()
        Dim cm As PointF = New PointF(270, 175)
        Dim r As Int32 = 150
        For wi As Int32 = 0 To 360 Step 360 \ tw(TrackBar1.Value)
            pList.Add(New PointF(cm.X + Math.Cos(wi * Math.PI / 180) * r, cm.Y _
              - Math.Sin(wi * Math.PI / 180) * r))
        Next
        Me.Refresh()
End Sub
End Class