<Window x:Class="WpfApp1.MainWindow"
          xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
          xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
          xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
          xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
          xmlns:local="clr-namespace:WpfApp1"
          mc:Ignorable="d"
          Title="MainWindow" Height="450" Width="800">

     <DockPanel>

          <!-- header -->
          <DockPanel DockPanel.Dock="Top" Background="lightgray" Height="60">
               <Label Content="Hello Top"/>
          </DockPanel>

          <!-- left panel -->
          <Border BorderThickness="0,0,2,0" DockPanel.Dock="Left" BorderBrush="DarkSlateGray" Width="220">
               <DockPanel DockPanel.Dock="Left" Background="lightgreen">
                    <Label Content="Hello1" />
               </DockPanel>
          </Border>

          <!-- right panel -->
          <DockPanel DockPanel.Dock="Right" HorizontalAlignment="Stretch">

               <Border BorderThickness="0,0,0,2" BorderBrush="DarkSlateGray" DockPanel.Dock="top">
                    <StackPanel Height="200" Background="lightblue">
                         <Label Content="Hello2" />
                    </StackPanel>
               </Border>

               <StackPanel Background="MediumSlateBlue">
                    <Label Content="Hello3" />
               </StackPanel>
          </DockPanel>

     </DockPanel>

</Window>