View difference between Paste ID: r7hsZMyJ and X4K9fdiG

 using System;
 using System.Collections.Generic;
 using System.Text;
 
 namespace create_class
 {
-	class Polygon
+	abstract class Polygon
 	{
 		public double Length  { get; protected set; }
 		public double Width{ get; protected set; }
 		abstract public double GetArea();
 	}
 }