title: Binding Height of RectangleGeometry
body: <p>I have a Border with a clipping mask as a RectangleGeometry added in a ResourceDictionary. I want the RectangleGeometry rectangle to change its Height depending on a value from code behind but don't know how to bind just the height.</p>
  
  <p>The Border with the clip:</p>
  
  <pre><code>&lt;Border Width="50" Height="50" Background="#F0F1F3" CornerRadius="4"&gt;
      &lt;Border.Clip&gt;
          &lt;RectangleGeometry Rect="0, 0, 50, 10" /&gt;
      &lt;/Border.Clip&gt;
  &lt;/Border&gt;
  </code></pre>
  
  <p>I found some answer to a similar question here:
  <a href="https://social.msdn.microsoft.com/Forums/vstudio/en-US/7c7dbdc9-3fdb-4893-ab1f-082df9594f25/rectanglegeometry-binding?forum=wpf" rel="nofollow noreferrer">https://social.msdn.microsoft.com/Forums/vstudio/en-US/7c7dbdc9-3fdb-4893-ab1f-082df9594f25/rectanglegeometry-binding?forum=wpf</a>
  And tried to do the same thing - add multibinding properties, but don't know what to do with these now:</p>
  
  <pre><code>&lt;RectangleGeometry.Rect&gt;
      &lt;MultiBinding Converter="{StaticResource Converter}"&gt;
          &lt;Binding ElementName="mainGrid" Path="Width"/&gt;
          &lt;Binding ElementName="mainGrid" Path="Height"/&gt;
      &lt;/MultiBinding&gt;
  &lt;/RectangleGeometry.Rect&gt;
  </code></pre>
  
  <p>How to define the origin point here? How to provide the Width and Height values? And what do I put in the ElementName?</p>