Dim p1() As Point = {New Point(0, 0), New Point(40, 0), New Point(30, 10), New Point(10, 10)}
    Dim p2() As Point = {New Point(0, 0), New Point(10, 10), New Point(10, 30), New Point(0, 40)}
    Dim p3() As Point = {New Point(0, 40), New Point(40, 40), New Point(30, 30), New Point(10, 30)}
    Dim p4() As Point = {New Point(40, 40), New Point(40, 0), New Point(30, 10), New Point(30, 30)}
    Dim p5() As Point = {New Point(10, 10), New Point(30, 10), New Point(30, 30), New Point(10, 30)}
    Dim Pol()() As Point = {p1, p2, p3, p4, p5}
   
    Public Shared Function IsInPolygon(poly As Point(), p As Point) As Boolean
        Dim p1 As Point, p2 As Point

        Dim inside As Boolean = False

        If poly.Length < 3 Then
            Return inside
        End If
       
        Dim oldPoint = New Point(poly(poly.Length - 1).X, poly(poly.Length - 1).Y)
       
        For i As Integer = 0 To poly.Length - 1
            Dim newPoint = New Point(poly(i).X, poly(i).Y)
            If newPoint.X > oldPoint.X Then
                p1 = oldPoint
                p2 = newPoint
            Else
                p1 = newPoint
                p2 = oldPoint
            End If
           
            If (newPoint.X < p.X) = (p.X <= oldPoint.X) AndAlso (p.Y - CLng(p1.Y)) * (p2.X - p1.X) < (p2.Y - CLng(p1.Y)) * (p.X - p1.X) Then
                inside = Not inside
            End If

            oldPoint = newPoint
        Next
        Return inside
    End Function
   
    Private Sub Form1_MouseMove(sender As Object, e As System.Windows.Forms.MouseEventArgs) Handles Me.MouseMove
        Dim g As Graphics = Me.CreateGraphics
        For Each p In Pol
            If IsInPolygon(p, e.Location) Then
                g.FillPolygon(Brushes.Red, p)
            Else
                g.FillPolygon(New SolidBrush(Me.BackColor), p)
            End If
            g.DrawPolygon(Pens.Black, p)

        Next
    End Sub

    Private Sub Form1_Paint(sender As Object, e As System.Windows.Forms.PaintEventArgs) Handles Me.Paint
        Dim g As Graphics = Me.CreateGraphics
        g.DrawPolygon(Pens.Black, p1)
        g.DrawPolygon(Pens.Black, p2)
        g.DrawPolygon(Pens.Black, p3)
        g.DrawPolygon(Pens.Black, p4)
        g.DrawPolygon(Pens.Black, p5)
    End Sub