Added Rectangle

Shapes/Validator.cs

@@ -0,0 +1,44 @@
+using System;
+using System.Collections.Generic;
+using System.Globalization;
+
+namespace Shapes
+{
+    public class Validator
+    {
+
+        public static void ValidateDouble(double value, string errorMessage)
+        {
+            if (double.IsInfinity(value) || double.IsNaN(value))
+                throw new ShapeException(errorMessage);
+        }
+
+        public static void ValidatePositiveDouble(double value, String errorMessage)
+        {
+            ValidateDouble(value, errorMessage);
+            if (value < 0)
+                throw new ShapeException(errorMessage);
+        }
+
+        public static void ValidateRectangle(Point point1, Point point2, Point point3, Point point4, String errorMessage)
+        {
+            var TOLERANCE = Double.Epsilon + Double.Epsilon;
+            var plumLine1 = new Line(point1, point3);
+            var plumLine2 = new Line(point2, point4);
+            var heightLine1 = new Line(point1, point4);
+            var heightLine2 = new Line( point2, point3);
+            var lengthLine1 = new Line(point1, point2);
+            var lengthLine2 = new Line(point4, point3);
+            if (Math.Abs(plumLine1.ComputeLength() - plumLine2.ComputeLength()) > TOLERANCE 
+                || Math.Abs(heightLine1.ComputeLength() - heightLine2.ComputeLength()) > TOLERANCE 
+                || Math.Abs(lengthLine1.ComputeLength() - lengthLine2.ComputeLength()) > TOLERANCE )
+            {
+                throw new ShapeException(errorMessage);
+            }
+            
+        }
+
+
+
+    }
+}