diff --git a/src/Avalonia.Base/Interactivity/RoutedEventArgs.cs b/src/Avalonia.Base/Interactivity/RoutedEventArgs.cs
index ccbb41b7dc..60a6b64677 100644
--- a/src/Avalonia.Base/Interactivity/RoutedEventArgs.cs
+++ b/src/Avalonia.Base/Interactivity/RoutedEventArgs.cs
@@ -2,29 +2,59 @@ using System;
 
 namespace Avalonia.Interactivity
 {
+    /// <summary>
+    /// Provices state information and data specific to a routed event.
+    /// </summary>
     public class RoutedEventArgs : EventArgs
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RoutedEventArgs"/> class.
+        /// </summary>
         public RoutedEventArgs()
         {
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RoutedEventArgs"/> class.
+        /// </summary>
+        /// <param name="routedEvent">The routed event associated with these event args.</param>
         public RoutedEventArgs(RoutedEvent? routedEvent)
         {
             RoutedEvent = routedEvent;
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="RoutedEventArgs"/> class.
+        /// </summary>
+        /// <param name="routedEvent">The routed event associated with these event args.</param>
+        /// <param name="source">The source object that raised the routed event.</param>
         public RoutedEventArgs(RoutedEvent? routedEvent, IInteractive? source)
         {
             RoutedEvent = routedEvent;
             Source = source;
         }
 
+        /// <summary>
+        /// Gets or sets a value indicating whether the routed event has already been handled.
+        /// </summary>
+        /// <remarks>
+        /// Once handled, a routed event should be ignored.
+        /// </remarks>
         public bool Handled { get; set; }
 
+        /// <summary>
+        /// Gets or sets the routed event associated with these event args.
+        /// </summary>
         public RoutedEvent? RoutedEvent { get; set; }
 
+        /// <summary>
+        /// Gets or sets the routing strategy (direct, bubbling, or tunneling) of the routed event.
+        /// </summary>
         public RoutingStrategies Route { get; set; }
 
+        /// <summary>
+        /// Gets or sets the source object that raised the routed event.
+        /// </summary>
         public IInteractive? Source { get; set; }
     }
 }
diff --git a/src/Avalonia.Controls/Control.cs b/src/Avalonia.Controls/Control.cs
index d0bf24947b..827bded115 100644
--- a/src/Avalonia.Controls/Control.cs
+++ b/src/Avalonia.Controls/Control.cs
@@ -559,8 +559,8 @@ namespace Avalonia.Controls
                 var sizeChangedEventArgs = new SizeChangedEventArgs(
                     SizeChangedEvent,
                     source: this,
-                    newSize: new Size(newValue.Width, newValue.Height),
-                    previousSize: new Size(oldValue.Width, oldValue.Height));
+                    previousSize: new Size(oldValue.Width, oldValue.Height),
+                    newSize: new Size(newValue.Width, newValue.Height));
 
                 RaiseEvent(sizeChangedEventArgs);
             }
diff --git a/src/Avalonia.Controls/SizeChangedEventArgs.cs b/src/Avalonia.Controls/SizeChangedEventArgs.cs
index d983e375c2..201a00a3fc 100644
--- a/src/Avalonia.Controls/SizeChangedEventArgs.cs
+++ b/src/Avalonia.Controls/SizeChangedEventArgs.cs
@@ -1,9 +1,4 @@
-using System;
-using System.Collections.Generic;
-using System.Linq;
-using System.Text;
-using System.Threading.Tasks;
-using Avalonia.Interactivity;
+using Avalonia.Interactivity;
 
 namespace Avalonia.Controls
 {
@@ -12,25 +7,41 @@ namespace Avalonia.Controls
     /// </summary>
     public class SizeChangedEventArgs : RoutedEventArgs
     {
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SizeChangedEventArgs"/> class.
+        /// </summary>
+        /// <param name="routedEvent">The routed event associated with these event args.</param>
         public SizeChangedEventArgs(RoutedEvent? routedEvent)
             : base (routedEvent)
         {
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SizeChangedEventArgs"/> class.
+        /// </summary>
+        /// <param name="routedEvent">The routed event associated with these event args.</param>
+        /// <param name="source">The source object that raised the routed event.</param>
         public SizeChangedEventArgs(RoutedEvent? routedEvent, IInteractive? source)
             : base(routedEvent, source)
         {
         }
 
+        /// <summary>
+        /// Initializes a new instance of the <see cref="SizeChangedEventArgs"/> class.
+        /// </summary>
+        /// <param name="routedEvent">The routed event associated with these event args.</param>
+        /// <param name="source">The source object that raised the routed event.</param>
+        /// <param name="previousSize">The previous size (or bounds) of the object.</param>
+        /// <param name="newSize">The new size (or bounds) of the object.</param>
         public SizeChangedEventArgs(
             RoutedEvent? routedEvent,
             IInteractive? source,
-            Size newSize,
-            Size previousSize)
+            Size previousSize,
+            Size newSize)
             : base(routedEvent, source)
         {
-            NewSize = newSize;
             PreviousSize = previousSize;
+            NewSize = newSize;
             HeightChanged = newSize.Height != previousSize.Height;
             WidthChanged = newSize.Width != previousSize.Width;
         }