using System;

​

public class Program

{

    static decimal pi = 3.14159M;

    static private decimal SACone(decimal r, decimal h)

    {

        double r2 = (double)r * (double)r;

        double h2 = (double)h * (double)h;

        double slant = Math.Sqrt(r2 + h2);

        return pi * r * r + pi * r * (decimal)slant;

    }

​

    static private decimal SASphere(decimal r)

    {

        decimal r2 = r * r;

        return 4M * pi * r2;

    }

​

    static private decimal SACyl(decimal r, decimal h)

    {

        decimal r2 = r * r;

        decimal h2 = h * h;

        return 2M * pi * r2 + 2M * pi * r * h;

    }

​

    static private decimal VofCone(decimal r, decimal h)

    {

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

    }

​

    static private decimal VofCyl(decimal r, decimal h)

    {

        return pi * r * r * h;

    }

​

    static private decimal VofSph(decimal r)

    {

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

    }

​

    public static void Main()

    {

        string restart = "hi";

        while (restart != "q")

        {

            Console.Clear();

            start:

                Console.WriteLine("Would you like to calculate the volume and surface area of a cone, a cylinder, or a sphere?");

            Console.WriteLine("Press 1 for the volume and surface area of a cone.");

            Console.WriteLine("Press 2 for the volume and surface area of a cylinder.");

            Console.WriteLine("Press 3 for the volume and surface area of a sphere.");

            decimal choice = decimal.Parse(Console.ReadLine());

            Console.Clear();

            if (choice == 1)

            {

                Console.WriteLine("What is the radius of your cone?");

                decimal input1 = decimal.Parse(Console.ReadLine());

                Console.WriteLine("What is the height of your cone?");

                decimal input2 = decimal.Parse(Console.ReadLine());

                Console.WriteLine("The volume of your cone is: " + VofCone(input1, input2).ToString("##.##"));

                Console.WriteLine("The surface area of your cone is: " + SACone(input1, input2).ToString("##.##"));

            }

            else if (choice == 2)

            {

                Console.WriteLine("What is the radius of your cylinder?");

                decimal input3 = decimal.Parse(Console.ReadLine());

                Console.WriteLine("What is the height of your cylinder?");

                decimal input4 = decimal.Parse(Console.ReadLine());

                Console.WriteLine("The volume of your cylinder is: " + VofCyl(input3, input4).ToString("##.##"));

                Console.WriteLine("The surface area of your cylinder is: " + SACyl(input3, input4).ToString("##.##"));

            }

            else if (choice == 3)

            {

                Console.WriteLine("What is the radius of your sphere?");

                decimal input5 = decimal.Parse(Console.ReadLine());

                Console.WriteLine("The volume of your sphere is " + VofSph(input5).ToString("##.##"));

                Console.WriteLine("The surface area of your sphere is: " + SASphere(input5).ToString("##.##"));

            }

            else

            {

                Console.WriteLine("You have entered an invalid number. Please enter a valid number.");

                goto start;

            }

​

            Console.WriteLine("Press q to quit or any other key to continue.");

            restart = Console.ReadLine();

        }

    }

}