using System;

public class Program

{

static double pi = 3.14159M

​

 static public double VofCylinder(double r, double h)

 {return pi*r*r*h;}

 static public double VofCone(double r, double h)

 {return (1M/3M)*pi*r*r*h;}

 static public double VofSphere(double r)

 {return(4M/3M)*pi*r*r*r;}

    public static void Main()

    {

        start:

        Console.WriteLine("Press 1 to calculate the area of a circle, 2 to calculate the circumference of a circle, and 3 to calculate both.");

        string choice = Console.ReadLine();

        if(choice == "1")

        {Console.WriteLine("Please Enter the volume of the cylinder.");

         double radius = double.Parse(Console.ReadLine());

         double height = double.Parse(Console.ReadLine());

         Console.WriteLine("The volume of the cylinder is: " + VofCylinder(radius, height).ToString("##.##")); 

        }

        else if(choice == "2")

        {Console.WriteLine("Please Enter the volume of the cone.");

         double radius = double.Parse(Console.ReadLine());

         double height = double.Parse(Console.ReadLine());

         Console.WriteLine("The volume of your come is: " + VofCone(radius, height).ToString("##.##")); 

        }

        else if(choice == "3")

        {Console.WriteLine("Please Enter the volume of the sphere.");

         double radius = double.Parse(Console.ReadLine());

         Console.WriteLine("The volume of the sphere is: " + VofSphere(radius).ToString("##.##")); 

         goto start;

        }

    }

}