Merge pull request #5521 from andreas-synnerdahl/issue-5471

Fix #5471 Corrected case of variable name 

src/Microsoft.DotNet.Wpf/src/PresentationCore/System/Windows/Media/RectangleGeometry.cs

@@ -439,9 +439,9 @@ internal override PathGeometryData GetPathGeometryData()
             else
             {   
                 ctx.BeginFigure(rect.TopLeft, true /* is filled */, true /* is closed */);
-                ctx.LineTo(Rect.TopRight, true /* is stroked */, false /* is smooth join */);
-                ctx.LineTo(Rect.BottomRight, true /* is stroked */, false /* is smooth join */);
-                ctx.LineTo(Rect.BottomLeft, true /* is stroked */, false /* is smooth join */);
+                ctx.LineTo(rect.TopRight, true /* is stroked */, false /* is smooth join */);
+                ctx.LineTo(rect.BottomRight, true /* is stroked */, false /* is smooth join */);
+                ctx.LineTo(rect.BottomLeft, true /* is stroked */, false /* is smooth join */);
             }
 
             ctx.Close();