title: WPF binding Width to Parent.Width*0.3
body: <p>I want to bind a control's Width to the parent's Width, but to a certain scale. Is there a way to do something like this:</p>
  
  <pre><code>&lt;Rectangle  Name="rectangle1" Width="{Binding ActualWidth*0.3, ElementName=thumbnailCanvas, UpdateSourceTrigger=PropertyChanged}" Height="{Binding ActualHeight, ElementName=thumbnailCanvas, UpdateSourceTrigger=PropertyChanged}"/&gt;
  </code></pre>