Here we are discussing an example that how can you rotate a rectangle in WPF.for rectangle rotation you need canvas,rectangle and some rotation method.
<Window x:Class="MainWindow"
 xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
 xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
 Title="MainWindow" Height="350" Width="525" HorizontalAlignment="Stretch" VerticalAlignment="Stretch" >
 <Canvas>
 <Rectangle Canvas.Left="80" Canvas.Top="70" Width="70" Height="40" Fill="Silver" />
 <Rectangle Canvas.Left="80" Canvas.Top="80" Width="70" Height="40" Fill="Black">
 <Rectangle.RenderTransform>
 <RotateTransform Angle="45" />
 </Rectangle.RenderTransform>
 </Rectangle>
 </Canvas>
</Window>

Main thing you need to define the rectangle coordinates and rotation angle.