Enlarge Button In Xaml

   
       

<Page xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml">

    <Button FontSize="12"
            HorizontalAlignment="Center" VerticalAlignment="Center">

        Expanding Button

        <Button.Triggers>
            <EventTrigger RoutedEvent="Button.Click">
                <BeginStoryboard>
                    <Storyboard TargetProperty="FontSize">
                        <DoubleAnimation From="12" To="48" 
                                         Duration="0:0:2"
                                         FillBehavior="Stop" />
                    </Storyboard>
                </BeginStoryboard>
            </EventTrigger>
        </Button.Triggers>
    </Button>
</Page>