title: Customize rounded corner radius of a WPF polyline
body: <p>is it possible to set the corner radius of a WPF polyline to a custom value.
  For a WPF border it is possible.
  In my opinion, the polyline can only set StrokeLineJoin="Round", but not the radius:</p>
  
  <pre><code>&lt;Polyline Points="0,0 0,100 200,100" StrokeLineJoin="Round" /&gt;
  </code></pre>
  
  <p>For border: CornerRadius="..." is possible:</p>
  
  <pre><code>&lt;Border CornerRadius="8" ... /&gt;
  </code></pre>
  
  <p>Is there an easy workaround/hack to achieve custom corner roundings (at line joins) of polylines?
  (e.g. Microsoft Visio is able to do this.)
  Thanks!</p>