title: Filled Arcs in WPF
body: <p>I am trying to draw a figure something like this:<img src="https://i.stack.imgur.com/PINuh.png" alt="Concentric arcs"></p>
  
  <p>I need to have a unique element for each arc segment that I can handle events on and recolor as I need. I am a bit unsure on how to create the proper geometries in WPF. I can easily calculate the four points for each arc segment from the radius of the circles and the angle from center. Using a radius of 100 for the outer circle and 50 for the inner, the four points in red are (clockwise from top left with origin at top of circle):</p>
  
  <pre><code>0,0
  70,30
  35,65
  0,50
  </code></pre>
  
  <p>Using these points I create a simple path to draw the segment: </p>
  
  <pre class="lang-xml prettyprint-override"><code>&lt;Path Stroke="Black" Fill="Black" StrokeThickness="1" &gt;
    &lt;Path.Data&gt;
      &lt;PathGeometry&gt;
        &lt;PathGeometry.Figures&gt;
          &lt;PathFigure StartPoint="0,0"&gt;
            &lt;PathFigure.Segments&gt;
              &lt;ArcSegment Point="70,30" /&gt;
              &lt;LineSegment Point="35,65" /&gt;
              &lt;ArcSegment Point="0,50" /&gt;
            &lt;/PathFigure.Segments&gt;
          &lt;/PathFigure&gt;
        &lt;/PathGeometry.Figures&gt;
      &lt;/PathGeometry&gt;
    &lt;/Path.Data&gt;
  &lt;/Path&gt;
  </code></pre>
  
  <p>But that just draws a trapezoid with straight lines. I know I can alter the Size on the ArcSegments, but I can't seem to figure out how that affects the curvature. I want the arcs to follow the main circle, but I am not sure how to express that. How can I make the arcs have the right curvature?</p>
  
  <p>Also, how do I express and add paths in the c# code behind,rather than in the xaml?</p>