Adding Rectangle to StackPanel
<Window x:Class="WpfApplication1.Window1" xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml" Title="Glyphs and Fonts" Height="300" Width="350" > <StackPanel> <Rectangle Width="200" Height="50" /> </StackPanel> </Window>