Making shapes in C#

using System;
namespace RectangleApplication {
   class Rectangle {
      double length;
      double width;
      public void Acceptdetails() {
          length = 5
          width = 4
          }
       public double GetArea() {
         return length * width;
      }
      public void Display() {
         Console.WriteLine("Length: {0}", length);
         Console.WriteLine("Width: {0}", width);
         Console.WriteLine("Area: {0}", GetArea());
      }
   }