Lessons/MainWindow.xaml

<Window x:Class="TestWpfApp.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:TestWpfApp"
        mc:Ignorable="d"
        Title="Проектdfghjkl" Height="450" Width="800">
    <Grid>
        <Grid.ColumnDefinitions>
            <ColumnDefinition Width="250"/>
            <ColumnDefinition Width="*"/>
        </Grid.ColumnDefinitions>
        <Grid.RowDefinitions>
            <RowDefinition Height="75"/>
            <RowDefinition Height="*"/>
            <RowDefinition Height="75"/>
        </Grid.RowDefinitions>
        <StackPanel Grid.Column="1" Grid.Row="1">
        <Button Width="125" Height="25" ></Button>
            <Button Width="125" Height="25" ></Button>
            <Button Width="125" Height="25" ></Button>
            <Button Width="125" Height="25"></Button>
        </StackPanel>
    </Grid>
</Window>