Added Rectangle

Shapes/Shape.cs

@@ -0,0 +1,20 @@
+using System.ComponentModel;
+using System.Diagnostics.Tracing;
+using System.Drawing;
+using System.Reflection.Metadata.Ecma335;
+
+namespace Shapes
+{
+    public abstract class Shape
+    {
+        public abstract Color Fill { get; set; }
+        public abstract Color Color { get; set; }
+        public abstract double Width { get; }
+        public abstract double Height { get; }
+        public abstract double ComputeArea();
+
+        public abstract void Scale(double scaleFactor);
+
+
+    }
+}