did a search on internet, could not find the solution. I think I missed something for below code to make the text wrap:
<Button x:Name="btnCustomerAging" Background="Green" BorderBrush="Green" Foreground="White" FontSize="33" HorizontalAlignment="Left" Margin="662,106,0,0" Grid.Row="1" VerticalAlignment="Top" Height="213" Width="238"> <TextWrapping> Customer Locations </TextWrapping> </Button>