test/WpfApp1/MainWindow.xaml

<Window x:Class="WpfApp1.MainWindow"
        xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
        xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
        xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
        xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
        xmlns:local="clr-namespace:WpfApp1"
        mc:Ignorable="d"
        Title="MainWindow" Height="450" Width="800">
    <Grid>
        <Button Content="Рассчитать" HorizontalAlignment="Left" Margin="16,48,0,0" VerticalAlignment="Top" Click="Button_Click"/>
        <Button Content="Сформировать квитанцию" HorizontalAlignment="Left" Margin="266,48,0,0" VerticalAlignment="Top"/>
        <Label Content="Введите время (Мин.) разговоров за месяц:" HorizontalAlignment="Left" Margin="10,10,0,0" VerticalAlignment="Top"/>
        
        <TextBox x:Name="MinTime" HorizontalAlignment="Left" Margin="266,16,0,0" 
                 TextWrapping="Wrap" 
                 Text="" 
                 MaxLength="4"
                 VerticalAlignment="Top" Width="151"/>
        
        <RadioButton x:Name="Tarif1" Content="Тариф 1" HorizontalAlignment="Left" Margin="466,16,0,0" VerticalAlignment="Top"/>
        <RadioButton x:Name="Tarif2" Content="Тариф 2" HorizontalAlignment="Left" Margin="466,51,0,0" VerticalAlignment="Top"/>
        
        <Label x:Name="SummText" Content="К оплате:" HorizontalAlignment="Left" Margin="16,95,0,0" VerticalAlignment="Top"/>
        <Label x:Name="SwerhNormText" Content="Минуты свверх установленной нормы:" HorizontalAlignment="Left" Margin="16,148,0,0" VerticalAlignment="Top" Background="White" Foreground="Red" FontWeight="Bold"/>

    </Grid>
</Window>