Я добавил контент по центру форму

Kovalev1App/MainWindow.xaml

@@ -5,4 +5,30 @@
         xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
         xmlns:local="clr-namespace:Kovalev1App"
         mc:Ignorable="d"
-        Title="MainWindow" Height="450" Width="800"/>
+        Title="MainWindow" Height="450" Width="1064.534">
+    <Grid Margin="-2,10,2,-10">
+        <Grid.RowDefinitions>
+            <RowDefinition Height="35*"/>
+            <RowDefinition Height="235*"/>
+            <RowDefinition Height="49*"/>
+        </Grid.RowDefinitions>
+        <Grid.ColumnDefinitions>
+            <ColumnDefinition Width="80*"/>
+            <ColumnDefinition Width="295*"/>
+            <ColumnDefinition Width="142*"/>
+        </Grid.ColumnDefinitions>
+        <Grid Grid.ColumnSpan="3" Grid.RowSpan="3">
+            <Grid.RowDefinitions>
+                <RowDefinition Height="*"/>
+                <RowDefinition Height="235*"/>
+                <RowDefinition Height="*"/>
+            </Grid.RowDefinitions>
+            <Grid.ColumnDefinitions>
+                <ColumnDefinition Width="*"/>
+                <ColumnDefinition Width="295*"/>
+                <ColumnDefinition Width="*"/>
+            </Grid.ColumnDefinitions>
+
+        </Grid>
+    </Grid>
+</Window>