Rotate the text 90 degrees using a RotateTransform

   
  

<Window x:Class="SDKSample.Window1"
  xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
  xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
  Title="Text Transform Samples"
  Background="FloralWhite"
  Height="640">

    <StackPanel Canvas.Left="0">
      <TextBlock FontFamily="Arial Black" FontSize="64" Foreground="Moccasin" Margin ="80, 10, 0, 0">
        Text Transforms
        <TextBlock.RenderTransform>
          <RotateTransform Angle="90" />
        </TextBlock.RenderTransform>
      </TextBlock>
    </StackPanel>
</Window>