Praktika/Pages/CustomerMenu.xaml

<Page x:Class="Авторизация.Pages.CustomerMenu"
      xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
      xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
      xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
      xmlns:d="http://schemas.microsoft.com/expression/blend/2008" 
      xmlns:local="clr-namespace:Авторизация.Pages"
      mc:Ignorable="d" 
      d:DesignHeight="300" d:DesignWidth="300"
      Title="CustomerMenu">

    <Grid>
        <Grid.RowDefinitions>
            <RowDefinition Height="*"/>
            <RowDefinition Height="70"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="*"/>
            <ColumnDefinition Width="257"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Button Content="Переход 1" Click="ButtonPage1_OnClick" Grid.Column="1" Margin="0,0,0,49" Grid.Row="1" />
        <Button Content="Переход 2" Click="ButtonPage2_OnClick" Grid.Column="1" Margin="0,24,0,25" Grid.Row="1" />
        <Button Content="Переход 3" Click="ButtonPage3_OnClick"  Grid.Column="1" Margin="0,49,0,0" Grid.Row="1"/>
    </Grid>
</Page>