A drawing program (Illustrator, Freehand, CorelDraw, etc.) would be more
accurate for this task as most allow you to adjust a numerical setting for
corner radius.  You should also be able to interpolate (automatically create
concentric rectangles) between the largest and smallest shapes.

That said, in PowerPoint you can adjust the corner radius using the yellow
diamond adjustment handle.  It's a visual adjustment, there aren't any
numerical settings to edit.  Make separate adjustments to each concentric
rectangle.

Best wishes,

Julie Terberg
MS PPT MVP
www.terbergdesign.com

You can do this with a quickie little VBA macro:

Select both and run this:

Sub RoundedShoulders()
  With ActiveWindow.Selection.ShapeRange
      .Item(2).Adjustments.Item(1) = _
      .Item(1).Adjustments.Item(1)
  End with
End Sub

But as long as you're gonna mess with vba, let it do more of the lifting.
Draw the first shape then run this while it's selected.  This dupes it, offsets
it and rounds it to match:

Sub RoundMyShoulders()

   Dim oSh As Shape
   Dim sngOffset As Single
   
   ' This controls how much smaller the "inset" shape will be all around
   sngOffset = 12  ' points
   
   With ActiveWindow.Selection.ShapeRange(1)
       
       ' Make a copy of the shape
       ' smaller than original by offset amount and centered atop it
       Set oSh = .Duplicate(1)
       oSh.Left = .Left + sngOffset
       oSh.Width = .Width - (sngOffset * 2)
       oSh.Top = .Top + sngOffset
       oSh.Height = .Height - (sngOffset * 2)
   
       oSh.Adjustments.Item(1) = .Adjustments.Item(1)
   
   End With

End Sub

-----------------------------------------
Steve Rindsberg, PPT MVP
PPT FAQ:  www.pptfaq.com
PPTools:  www.pptools.com
================================================

Thank you for the suggestions.  I can do it easy in corelDraw.  I'll give the
macro a try as well...