Hi Felix:
Here is a macro that will make it automatically:
Sub Macro1()
Range("G11").Select
With ActiveSheet
..Shapes.AddShape(msoShapeIsoscelesTriangle, 267.75, 234.75, 87#, 88.5).Select
..Shapes(1).Select
End With
Selection.ShapeRange.ScaleWidth 4.09, msoFalse, msoScaleFromTopLeft
Selection.ShapeRange.ScaleHeight 0.97, msoFalse, msoScaleFromTopLeft
Range("G12").Select
End Sub
Open a new spreadsheet, install the macro and run it.