I am having performance issues when rendering/rotating WPF triangles

If I had a WPF triangle being displayed and it will be rotated to some degree around a centrepoint, I can do it one of two ways:

1. Programatically determine the points and their offset in the backend, use XAML to simply place them on the canvas where they belong, it would look like this:

   <Path Stroke="Black">
      <Path.Data>
         <PathGeometry>
            <PathFigure StartPoint ="{Binding CalculatedPointA, Mode=OneWay}">
               <LineSegment Point="{Binding CalculatedPointB, Mode=OneWay}" />
               <LineSegment Point="{Binding CalculatedPointC, Mode=OneWay}" />
               <LineSegment Point="{Binding CalculatedPointA, Mode=OneWay}" />
            </PathFigure>
         </PathGeometry>
      </Path.Data>
   </Path>
   

2. Generate the 'same' triangle every time, and then use a RenderTransform (Rotate) to put it where it belongs. In this case, the rotation calculations are being obfuscated, because I don't have any access to how they are being done.

   <Path Stroke="Black">
      <Path.Data>
         <PathGeometry>
            <PathFigure StartPoint ="{Binding TriPointA, Mode=OneWay}">
               <LineSegment Point="{Binding TriPointB, Mode=OneWay}" />
               <LineSegment Point="{Binding TriPointC, Mode=OneWay}" />
               <LineSegment Point="{Binding TriPointA, Mode=OneWay}" />
            </PathFigure>
         </PathGeometry>
      </Path.Data>
      <Path.RenderTransform>
         <RotateTransform CenterX="{Binding Centre.X, Mode=OneWay}" 
                          CenterY="{Binding Centre.Y, Mode=OneWay}"
                          Angle="{Binding Orientation, Mode=OneWay}" />
      </Path.RenderTransform>
   </Path>
   

My question is which one is faster?

I know I should test it myself but how do I measure the render time of objects with such granularity. I would need to be able to time how long the actual rendering time is for the form, but since I'm not the one that's kicking off the redraw, I don't know how to capture the start time.