Using the idea of object-oriented polymorphism to find the area and perimeter of circle and rectangle respectively

//using the idea of object-oriented polymorphism to find the area and perimeter of circle and rectangle respectivelyStatic voidMain (string[] args) { Sharp Sharp=NewCircle (5); DoubleArea=Sharp .            Getarea (); DoublePerimeter=Sharp .            Getperimeter (); Console.WriteLine ("area is {0}, perimeter is {1}", Area,perimeter);        Console.readkey (); }         Public Abstract classSharp { Public Abstract DoubleGetarea ();  Public Abstract DoubleGetperimeter (); }         Public classCircle:sharp {Private Double_r;  Public DoubleR {Get{return_r;} Set{_r =value;} }             PublicCircle (Doubler) { This. R =R; }             Public Override DoubleGetarea () {returnMath.PI * This. R This.            R }             Public Override DoubleGetperimeter () {return 2* Math.PI * This.            R }        }         Public classSquare:sharp {Private Double_height;  Public DoubleHeight {Get{return_height;} Set{_height =value;} }            Private Double_width;  Public DoubleWidth {Get{return_width;} Set{_width =value;} }             PublicSquare (DoubleHeightDoublewidth) {                 This. Height =height;  This. Width =width; }             Public Override DoubleGetarea () {return  This. Height * This.            Width; }             Public Override DoubleGetperimeter () {return( This. Height + This. Width) *2; }        }

Using the idea of object-oriented polymorphism to find the area and perimeter of circle and rectangle respectively