<Canvas
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
	Width="500" Height="500">
	
	<Path x:Name="path" Width="0" Height="0" Canvas.Left="0" Canvas.Top="0" Stretch="Fill" Data="F1 M 0,0L 100,10" StrokeThickness="10" StrokeLineJoin="Round" Stroke="Red">
  	<Path.Triggers>
		<EventTrigger RoutedEvent="Path.Loaded">
			<BeginStoryboard>
				<Storyboard x:Name="animation" BeginTime="0:0:1">
					<DoubleAnimationUsingKeyFrames
						Storyboard.TargetName="path"
						Storyboard.TargetProperty="(Path.Width)">
							<LinearDoubleKeyFrame Value="500" KeyTime="0:0:4"/>
					</DoubleAnimationUsingKeyFrames>
					<DoubleAnimationUsingKeyFrames
						Storyboard.TargetName="path"
						Storyboard.TargetProperty="(Path.Height)">
							<LinearDoubleKeyFrame Value="500" KeyTime="0:0:8"/>
					</DoubleAnimationUsingKeyFrames>
				</Storyboard>
			</BeginStoryboard>
		</EventTrigger>
	</Path.Triggers>
	</Path>
 
</Canvas>
