question 4

using system;
{
class Question4
{
    static void Main()

        radius = new Radius(radius);
    circle.setradius(userinput)

    Console.WriteLine("Please Enter the Circle's Radius");
radius = Console.ReadLine();

    Console.Write ("The area of the circle is {0}");
    Console.Write ("The Diameter of the circle is {1}");
    Console.Write ("The Circumference of the circle is {2}");
}
}