C#

1. Remove the protected modifier from the <set>set accessors. The properties can then be set from any code.
   
   C#

   abstract class Polygon
   {
       public double Length { get; set; }
       public double Width { get; set; }
       abstract public double GetArea();
   }

2. Add a public method to the Polygon or Rectangle class to change the property values. This method can then be called from any code.
   
   C#

   abstract class Polygon
   {
       public double Length { get; protected set; }
       public double Width { get; protected set; }
       abstract public double GetArea();
       
       public void ChangeDimensions(double newLength, double newHeight)
       {
           Length = newLength;
           Height = newHeight;
       }
   }

3. If you want to preserve the immutability[^] of the class (Hint: This is almost always a good idea!), you'll need to create a new instance of the class with the new dimensions.

Member 11025924 wrote:

I want the console application run every time i pass the textbox content.

Kornfeld Eliyahu Peter wrote:

but IE has its ways...