Нахождение пары точек, расстояние между которым наибольшее

Dim n As Byte, i As Byte, j As Byte
 
Private Sub Pic1_MouseUp(Button As Integer, Shift As Integer, x As Single, y As Single)
Pic1.DrawWidth = 7
Pic1.PSet (x, y), &H8000&
End Sub
 
Private Sub CmdVis_Click()
Lbl2.Visible = True
Lbl3.Visible = True
Pic1.DrawWidth = 1
Pic1.Scale (-10, 10)-(10, -10)
For i = 1 To 19
Pic1.Line (-10 + i, -10)-(-10 + i, 10)
Pic1.Line (-10, -10 + i)-(10, -10 + i)
Next i
Pic1.DrawWidth = 3
Pic1.Line (0, -10)-(0, 10)
Pic1.Line (-10, 0)-(10, 0)
Pic1.Line (9.2, -0.2)-(10, 0)
Pic1.Line (9.2, 0.2)-(10, 0)
Pic1.Line (0.2, 9.2)-(0, 10)
Pic1.Line (-0.2, 9.2)-(0, 10)
Pic1.Line (9.2, -0.2)-(9.2, 0.2)
Pic1.Line (-0.2, 9.2)-(0.2, 9.2)
End Sub
 
Private Sub CmdSet_Click()
n = Val(Txt1.Text)
End Sub
 
Private Sub Form_Load()
Lbl2.Visible = False
Lbl3.Visible = False
End Sub