Sub Макрос1()
    Range("I9:I11").Select
    Selection.ClearContents
End Sub

Sub Пример()
    With ActiveSheet
        TriangleInterpol2 .Cells(13, "D"), .Cells(10, "S"), .Cells(21, "P")
        TriangleInterpol2 .Cells(10, "S"), .Cells(24, "AA"), .Cells(21, "P")
        TriangleInterpol2 .Cells(24, "AA"), .Cells(35, "G"), .Cells(21, "P")
        TriangleInterpol2 .Cells(35, "G"), .Cells(13, "D"), .Cells(21, "P")
    End With
End Sub

Sub TEST()
    Dim RngA As Range, RngB As Range, RngC As Range
    Dim Ax#, Ay#, Bx#, By#, Cx#, Cy#
    
    Sheets.Add
    Cells.RowHeight = 12.75
    Cells.ColumnWidth = 2.29
    
    Set RngA = Cells(13, 17)
    Set RngB = Cells(10, 32)
    Set RngC = Cells(21, 29)
    RngA.Interior.Color = vbGreen: RngA.Value = 12
    RngB.Interior.Color = vbGreen: RngB.Value = 35
    RngC.Interior.Color = vbGreen: RngC.Value = -8
    
    Ax = (RngA.Left + RngA.Offset(0, 1).Left) / 2
    Ay = (RngA.Top + RngA.Offset(1, 0).Top) / 2
    Bx = (RngB.Left + RngB.Offset(0, 1).Left) / 2
    By = (RngB.Top + RngB.Offset(1, 0).Top) / 2
    Cx = (RngC.Left + RngC.Offset(0, 1).Left) / 2
    Cy = (RngC.Top + RngC.Offset(1, 0).Top) / 2
      
    With ActiveSheet.Shapes
        .AddConnector(msoConnectorStraight, Ax, Ay, Bx, By).Select
        .AddConnector(msoConnectorStraight, Bx, By, Cx, Cy).Select
        .AddConnector(msoConnectorStraight, Cx, Cy, Ax, Ay).Select
    End With
     
    Call CentrOtrezka(Ax, Ay, Bx, By, RngA.Value, RngB.Value)
    Call CentrOtrezka(Bx, By, Cx, Cy, RngB.Value, RngC.Value)
    Call CentrOtrezka(Cx, Cy, Ax, Ay, RngC.Value, RngA.Value)
    
End Sub
 
Sub CentrOtrezka(x1#, y1#, x2#, y2#, v1&, v2&)
    Dim x#, y#
    x = (x1 + x2) / 2
    y = (y1 + y2) / 2
 
    With ActiveSheet.Shapes.AddLine(x, y, x, y)
        .TopLeftCell.Select
        .Delete
    End With
    Selection.Interior.Color = vbYellow
    Selection.Value = CLng((v1 + v2) / 2)
End Sub