Figure's area, perimeter or both

using System;
using System.Linq;

namespace _02_Experiment
{
    class Program
    {
        static public void Main()
        {
            Console.Write("What figure you want to work with (Triangle / Rectangle / Circle / Square) ");
            string figure = Console.ReadLine().ToLower();
            if (figure == "triangle")
            {
                Triangle triangle = new Triangle();
            }
            else if (figure == "rectangle")
            {
                Rectangle rectangle = new Rectangle();
            }
            else if (figure == "circle")
            {
                Circle circle = new Circle();
                for (int i = 0; i < 1; i++)
                {
                    Console.Write("Your input is a (Radius / Diameter) ");
                    string input = Console.ReadLine().ToLower();
                    double diaOrRad = 0;

                    if (input == "diameter")
                    {
                        try
                        {
                            Console.Write("Diameter's values is: ");
                            diaOrRad += double.Parse(Console.ReadLine());
                            if (Verification.TooSmallValues(diaOrRad))
                            {
                                i--;
                                continue;
                            }
                            else
                            {
                                circle.Radius = diaOrRad / 2;
                            }
                            circle.Choose();
                        }
                        catch (FormatException)
                        {
                            Console.WriteLine("Please enter numbers for the element's value!\n");
                            i--;
                            continue;
                        }
                    }
                    else if (input == "radius")
                    {
                        try
                        {
                            Console.Write("Radius' values is: ");
                            diaOrRad += double.Parse(Console.ReadLine());
                            if (Verification.TooSmallValues(diaOrRad))
                            {
                                i--;
                                continue;
                            }
                            else
                            {
                                circle.Radius = diaOrRad;
                            }
                            circle.Choose();
                        }
                        catch
                        {
                            Console.WriteLine("Please enter numbers for the element's value!\n");
                            i--;
                            continue;
                        }
                    }
                    else
                    {
                        Console.WriteLine("\nPlease choose for your input one of the " +
                            "options we have presented you in the upper line!\n");
                        i--;
                        continue;
                    }
                }
            }
            else if (figure == "square")
            {
                Square square = new Square();
                for (int i = 0; i < 1; i++)
                {
                    Console.Write("Your input is a (Side / Diagonal) ");
                    string input = Console.ReadLine().ToLower();
                    double sideOrDia = 0;

                    if (input == "side")
                    {
                        try
                        {
                            Console.Write("Side's values is: ");
                            sideOrDia += double.Parse(Console.ReadLine());
                            if (Verification.TooSmallValues(sideOrDia))
                            {
                                i--;
                                continue;
                            }
                            else
                            {
                                square.Side = sideOrDia;
                            }
                            square.Choose();
                        }
                        catch (FormatException)
                        {
                            Console.WriteLine("Please enter numbers for the element's value!\n");
                            i--;
                            continue;
                        }
                    }
                    else if (input == "diagonal")
                    {
                        try
                        {
                            Console.Write("Diagonal's value is: ");
                            sideOrDia += double.Parse(Console.ReadLine());
                            if (Verification.TooSmallValues(sideOrDia))
                            {
                                i--;
                                continue;
                            }
                            else
                            {
                                square.Diagonal = sideOrDia;
                            }
                            square.Choose();
                        }
                        catch
                        {
                            Console.WriteLine("Please enter numbers for the element's value!\n");
                            i--;
                            continue;
                        }
                    }
                    else
                    {
                        Console.WriteLine("\nPlease choose for your input one of the " +
                            "options we have presented you in the upper line!\n");
                        i--;
                        continue;
                    }
                }
            }

        }
    }

    static class Verification
    {
        static public bool FirstUnequalityTheorem(double side1, double side2, double side3)
        {
            if (side1 < side2 + side3 && side2 < side1 + side3 && side3 < side1 + side2)
            {
                return true;
            }
            else
            {
                return false;
            }
        }

        static public bool TooSmallValues(double value)
        {
            if (value <= 0)
            {
                Console.WriteLine("\nYou have entered too small values! Please enter again the type of your input with a correct value!\n");
                return true;
            }
            else
            {
                return false;
            }
        }
    }
class Triangle
    {
        private double area;
        private double perimeter;
        private static int count = 0;

        public Triangle()
        {
            Console.Write("You want to find (Area / Perimeter / Both) of a triangle: ");
            string faceOrArea = Console.ReadLine().ToLower();

            if (faceOrArea == "area")
            {
                Area();
            }
            else if (faceOrArea == "perimeter")
            {
                Perimeter();
            }
            else if (faceOrArea == "both")
            {
                AreaAndPerimeter();
            }
            else
            {
                Console.WriteLine("\nPlease choose for your input one of the options we have presented you in the upper line!\n");
            }
        }

        private void AreaAndPerimeter()
        {
            string[] order = new string[] { "a", "b", "c" };
            double[] values = new double[3];

            Console.WriteLine("\nEnter the values of the three sides of the triangle:");

            for (int i = 0; i < 3; i++)
            {
                Console.Write($"{order[i]} = ");
                values[i] = double.Parse(Console.ReadLine());

                if (Verification.TooSmallValues(values[i]))
                {
                    i--;
                    continue;
                }
            }

            if (Verification.FirstUnequalityTheorem(values[0], values[1], values[2]))
            {
                perimeter = values[0] + values[1] + values[2];
                area = HeronFormula(values[0], values[1], values[2]);
                Console.WriteLine("\nThe perimeter of that triangle is: {0:N2} and his area is {1:N2}", perimeter, area);
            }
            else
            {
                Console.WriteLine("\nIt is impossible to exist such a triangle according to the UNEQUALITY THEOREM ONE!\n");
                StartAgain();
            }
        }

        private void Perimeter()
        {
            string[] order = new string[] { "a", "b", "c" };
            double[] values = new double[3];

            Console.Write("\nEnter the values of the three sides of the triangle: \n");

            for (int i = 0; i < 3; i++)
            {
                Console.Write($"{order[i]} = ");
                values[i] = double.Parse(Console.ReadLine());

                if (Verification.TooSmallValues(values[i]))
                {
                    i--;
                    continue;
                }
            }

            if (Verification.FirstUnequalityTheorem(values[0], values[1], values[2]))
            {
                perimeter = values[0] + values[1] + values[2];
                Console.WriteLine("\nThe perimeter of that triangle is: {0:N2}", perimeter);
            }
            else
            {
                Console.WriteLine("\nIt is impossible to exist such a triangle according to the UNEQUALITY THEOREM ONE!\n");
                StartAgain();
            }
        }

        private void Area()
        {
            string[] order = new string[] { "first", "second", "third" };
            string[] elements = new string[3];
            double[] values = new double[3];

            for (int i = 0; i < 3; i++)
            {
                Console.Write($"Your {order[i]} input is a (Side / Height / Angle) ");
                elements[i] = Console.ReadLine().ToLower();

                //Wrong element input;
                if (!(elements[i] == "side" || elements[i] == "height" || elements[i] == "angle"))
                {
                    Console.WriteLine("\nPlease choose for your input one of the options we have presented you in the upper line!\n");
                    i--;
                    continue;
                }

                Console.Write("Its vaue is ");
                values[i] = double.Parse(Console.ReadLine());

                //Wrong value input;
                if (Verification.TooSmallValues(values[i]))
                {
                    i--;
                    continue;
                }
                //Wrong angle value input;
                else if (elements[i] == "angle" && (values[i] <= 0 || values[i] >= 180))
                {
                    Console.WriteLine("\nYou have impossible values for angle in a triangle! Please enter again the type of your input with a correct value!\n");
                    i--;
                    continue;
                }

                //Area found by a base side and its height:
                if ((elements[0] == "side" || elements[1] == "side") && (elements[0] == "height" || elements[1] == "height"))
                {
                    area = BaseAndHeight(values[Array.IndexOf(elements, "side")], values[Array.IndexOf(elements, "height")]);
                    if (area != 0)
                    {
                        Console.WriteLine("The area of that triangle is: {0:N2}", area);
                        break;
                    }
                    else
                    {
                        Console.Write("Do you know the base side of that triangle (Yes / No) ");
                        string ifKnow = Console.ReadLine().ToLower();
                        if (ifKnow == "yes")
                        {
                            Console.Write("Its vaue is ");
                            double sideIfKnow = double.Parse(Console.ReadLine());
                            area = BaseAndHeight(sideIfKnow, values[Array.IndexOf(elements, "height")]);
                            Console.WriteLine("The area of that triangle is: {0:N2}", area);
                            break;
                        }
                        else
                        {
                            Console.WriteLine("There is no such a formula to calculate the triangle's area using your input data.");
                            StartAgain();
                        }
                    }
                }
            }

            //Finding out how many the sides in the triangle are:
            int numOfSides = 0;
            foreach (string element in elements)
            {
                if (element == "side")
                {
                    numOfSides++;
                }
            }

            //Area of a rectangular triangle:
            //Area found by an angle and the other two sides:
            bool predict = elements.Contains("angle");
            if (predict)
            {

                //Area of a rectangular triangle:
                double angle = values[Array.IndexOf(elements, "angle")];
                if (angle == 90 && numOfSides == 2)
                {
                    area = RectangularTriangle(values[Array.IndexOf(elements, "side")], values[Array.LastIndexOf(elements, "side")]);
                    Console.WriteLine("The area of that triangle is: {0:N2}", area);
                }

                //Area found by an angle and the other two sides:
                else if (angle != 90 && numOfSides == 2)
                {
                    area = AngleAndTwoSides(values[Array.IndexOf(elements, "angle")], values[Array.IndexOf(elements, "side")], values[Array.LastIndexOf(elements, "side")]);
                    Console.WriteLine("The area of that triangle is: {0:N2}", area);
                }
            }

            //Area found using The Heron's formula and checking the first unequality theorem:
            else
            {
                if (numOfSides == 3)
                {
                    if (Verification.FirstUnequalityTheorem(values[0], values[1], values[2]))
                    {
                        area = HeronFormula(values[0], values[1], values[2]);
                        Console.WriteLine("The area of that triangle is: {0:N2}", area);
                    }
                    else
                    {
                        Console.WriteLine("\nIt is impossible to exist such a triangle according to the UNEQUALITY THEOREM ONE!\n");
                        StartAgain();
                    }
                }
                else if (numOfSides != 3 && area == 0)
                {
                    Console.WriteLine("There is no way to calculate the area of the triangle!");
                    StartAgain();
                }
            }
        }

        private double BaseAndHeight(double side, double height)
        {
            Console.Write("Is this the base side of the height (Yes / No) ");
            string yesOrNo = Console.ReadLine().ToLower();
            if (yesOrNo == "yes")
            {
                return side * height / 2;
            }
            else if (yesOrNo == "no")
            {
                return 0.0;
            }
            else
            {
                Console.WriteLine("You entered incorrect values");
                StartAgain();
                return 0.0;
            }
        }

        private double RectangularTriangle(double side1, double side2)
        {
            Console.WriteLine("Do these two sides form the right angle (Yes / No) ");
            string yesOrNo = Console.ReadLine().ToLower();
            if (yesOrNo == "yes")
            {
                return side1 * side2 / 2;
            }
            else
            {
                StartAgain();
                return 0.0;
            }
        }

        private double AngleAndTwoSides(double angle, double side1, double side2)
        {
            Console.Write("Is this angle between the two other sides (Yes / No) ");
            string yesOrNo = Console.ReadLine().ToLower();
            if (yesOrNo == "yes")
            {
                return side1 * side2 * Math.Abs(Math.Sin(angle * Math.PI / 180)) / 2;
            }
            else
            {
                StartAgain();
                return 0.0;
            }
        }

        private double HeronFormula(double side1, double side2, double side3)
        {
            double halfPerimeter = (side1 + side2 + side3) / 2;
            return Math.Sqrt(halfPerimeter * (halfPerimeter - side1) * (halfPerimeter - side2) * (halfPerimeter - side3));
        }

        static public void StartAgain()
        {
            Console.Write("Do you want to start from the beginning (Yes / No) ");
            string startAgain = Console.ReadLine().ToLower();
            if (startAgain == "yes")
            {
                Console.Clear();
                Program.Main();
            }
            else if (startAgain == "no")
            {
                Console.WriteLine("Thank you for the time spent.");
            }
            else
            {
                Console.WriteLine("\nPlease choose for your input one of the options we have presented you in the upper line!\n");
                StartAgain();
            }
        }

        private void End(bool end)
        {
            if (end == true)
            {
                Console.WriteLine("\nThank you for your participation!");
            }
        }

        ~Triangle()
        {
            bool end = true;
            if (count > 0)
            {
                end = false;
            }
            End(end);
            count++;
        }
    }
class Square
    {
        private double area;
        private double perimeter;
        private double diagonal;
        private double side;

        public double Side
        {
            get
            {
                return side;
            }
            set
            {
                side += value;
            }
        }

        public double Diagonal
        {
            get
            {
                return diagonal;
            }
            set
            {
                diagonal += value;
            }
        }

        public void Choose()
        {
            for (int i = 0; i < 1; i++)
            {
                Console.Write("You want to find (Area / Perimeter / Both) of a circle: ");
                string faceOrArea = Console.ReadLine().ToLower();

                if (faceOrArea == "area")
                {
                    Area();
                }
                else if (faceOrArea == "perimeter")
                {
                    Perimeter();
                }
                else if (faceOrArea == "both")
                {
                    AreaAndPerimeter();
                }
                else
                {
                    Console.WriteLine("\nPlease choose for your input one of the options we have presented you in the upper line!\n");
                }
            }


        }
        private void Area()
        {
            area = Math.Pow(side, 2);
            Console.WriteLine(area);
        }
        private void Perimeter()
        {
            perimeter = 4 * side;
            Console.WriteLine(perimeter);
        }
        private void AreaAndPerimeter()
        {
            area = Math.Pow(side, 2);
            perimeter = 4 * side;
            Console.WriteLine("The area of the square is: {0:N2}", area);
            Console.WriteLine("The perimeter of the square is: {0:N2}", perimeter);
        }
    }
class Rectangle
    {
        private static double area;
        private static double perimeter;
        private static int count = 0;

        public Rectangle()
        {
            Console.Write("You want to find (Area / Perimeter / Both) of a rectangle: ");
            string faceOrArea = Console.ReadLine().ToLower();

            for (int i = 0; i < 1; i++)
            {
                if (faceOrArea == "area")
                {
                    Area();
                }
                else if (faceOrArea == "perimeter")
                {
                    Perimeter();
                }
                else if (faceOrArea == "both")
                {
                    AreaAndPerimeter();
                }
                else
                {
                    Console.WriteLine("\nPlease choose for your input one of the options we have presented you in the upper line!\n");
                    i--;
                    continue;
                }
            }
        }

        private void Area()
        {
            string[] order = new string[] { "first", "second" };
            string[] elements = new string[2];
            double[] values = new double[2];

            for (int i = 0; i < 2; i++)
            {
                Console.Write($"Your {order[i]} input is a (Side / Perimeter / Diagonal) ");
                elements[i] = Console.ReadLine().ToLower();

                //Wrong element input;
                if (!(elements[i] == "side" || elements[i] == "perimeter" || elements[i] == "diagonal"))
                {
                    Console.WriteLine("\nPlease choose for your input one of the options we have presented you in the upper line!\n");
                    i--;
                    continue;
                }

                Console.Write("Its vaue is ");
                try
                {
                    values[i] = double.Parse(Console.ReadLine());

                    //Wrong value input;
                    if (Verification.TooSmallValues(values[i]))
                    {
                        i--;
                        continue;
                    }
                }
                catch (FormatException)
                {
                    Console.WriteLine("Please enter numbers for the element's value!\n");
                    i--;
                    continue;
                }
            }

            if (elements[0] == "side" && elements[1] == "side")
            {
                area = AreaOfTwoSides(values[0], values[1]);
            }
            else if ((elements[0] == "perimeter" || elements[1] == "perimeter") && (elements[0] == "side" || elements[1] == "side"))
            {
                area = AreaOfPerimeterAndSide(values[Array.IndexOf(elements, "perimeter")], values[Array.IndexOf(elements, "side")]);
            }
            else if ((elements[0] == "diagonal" || elements[1] == "diagonal") && (elements[0] == "side" || elements[1] == "side"))
            {
                area = AreaOfDiagonalAndSide(values[Array.IndexOf(elements, "diagonal")], values[Array.IndexOf(elements, "side")]);
            }
            else
            {
                Console.WriteLine("There is no such a formula to calculate the rectangle's area using your input data.");
            }

            if (area != 0)
            {
                Console.WriteLine("The area of the rectangle is: {0:N2}", area);
            }
            else
            {
                Console.WriteLine("Something with your input was wrong!");
                StartAgain();
            }
        }

        private void Perimeter()
        {
            string[] order = new string[] { "a", "b" };
            double[] values = new double[2];

            Console.Write("\nEnter the values of two adjacent sides of the rectangle:\n");

            for (int i = 0; i < 2; i++)
            {
                try
                {
                    Console.Write($"{order[i]} = ");
                    values[i] = double.Parse(Console.ReadLine());

                    if (Verification.TooSmallValues(values[i]))
                    {
                        i--;
                        continue;
                    }
                }
                catch (FormatException)
                {
                    Console.WriteLine("Please enter numbers for the element's value!\n");
                    i--;
                    continue;
                }
            }
            perimeter = PerimeterOfTwoSides(values[0], values[1]);
            if (perimeter != 0)
            {
                Console.WriteLine("The perimeter of the rectangle is: {0:N2}", perimeter);
            }
            else
            {
                Console.WriteLine("Something with your input was wrong!");
                StartAgain();
            }
        }

        private void AreaAndPerimeter()
        {
            string[] order = new string[] { "a", "b" };
            double[] values = new double[2];

            Console.Write("\nEnter the values of two adjacent sides of the rectangle:\n");

            for (int i = 0; i < 2; i++)
            {
                try
                {
                    Console.Write($"{order[i]} = ");
                    values[i] = double.Parse(Console.ReadLine());

                    if (Verification.TooSmallValues(values[i]))
                    {
                        i--;
                        continue;
                    }
                }
                catch (FormatException)
                {
                    Console.WriteLine("Please enter numbers for the element's value!\n");
                    i--;
                    continue;
                }
            }
            area = AreaOfTwoSides(values[0], values[1]);
            if (area != 0)
            {
                perimeter = 2 * (values[0] + values[1]);
                Console.WriteLine("The area of the rectangle is: {0:N2}", area);
                Console.WriteLine("The perimeter of the rectangle is: {0:N2}", perimeter);
            }

        }

        private double AreaOfDiagonalAndSide(double d, double side)
        {
            double faceRect = side * Math.Sqrt(Math.Pow(d, 2) - Math.Pow(side, 2));
            if (d > side)
            {
                return faceRect;
            }
            else
            {
                Console.WriteLine("\nYou have entered impossible values for the diagonal!");
                StartAgain();
                return 0.0;
            }
        }

        private double AreaOfPerimeterAndSide(double p, double side)
        {
            if (p <= 2 * side)
            {
                Console.WriteLine("You have entered an incorrect input!");
                return 0.0;
            }
            else
            {
                return (p * side - 2 * Math.Pow(side, 2)) / 2;
            }
        }

        private double AreaOfTwoSides(double side1, double side2)
        {
            if (side1 == side2)
            {
                Console.Write("\nYou entered two equal values. Do you agree with your input (Yes / No) ");
                string square = Console.ReadLine().ToLower();
                if (square == "yes")
                {
                    return side1 * side2;
                }
                else
                {
                    StartAgain();
                    return 0.0;
                }
            }
            else
            {
                return side1 * side2;
            }
        }

        private double PerimeterOfTwoSides(double side1, double side2)
        {
            if (side1 == side2)
            {
                Console.Write("\nYou entered two equal values. Do you agree with your input (Yes / No) ");
                string square = Console.ReadLine().ToLower();
                if (square == "yes")
                {
                    return 2 * (side1 + side2);
                }
                else
                {
                    StartAgain();
                    return 0.0;
                }
            }
            else
            {
                return 2 * (side1 + side2);
            }
        }

        static public void StartAgain()
        {
            Console.Write("\nDo you want to start from the beginning (Yes / No) ");
            string startAgain = Console.ReadLine().ToLower();
            if (startAgain == "yes")
            {
                Console.Clear();
                Program.Main();
            }
            else if (startAgain == "no")
            {
                Console.WriteLine("Thank you for the time spent.");
            }
            else
            {
                Console.WriteLine("\nPlease choose for your input one of the options we have presented you in the upper line!\n");
                StartAgain();
            }
        }

        private void End(bool end)
        {
            if (end == true)
            {
                Console.WriteLine("\nThank you for your participation!");
            }
        }

        ~Rectangle()
        {
            bool end = true;
            if(count > 0)
            {
                end = false;
            }
            End(end);
            count++;
        }
    }
class Circle
    {
        private double area;
        private double perimeter;
        private double radius;
        private static int count = 0;

        public double Radius
        {
            get
            {
                return radius;
            }
            set
            {
                radius += value;
            }
        }

        public void Choose()
        {
            for (int i = 0; i < 1; i++)
            {
                Console.Write("You want to find (Area / Perimeter / Both) of a circle: ");
                string faceOrArea = Console.ReadLine().ToLower();

                if (faceOrArea == "area")
                {
                    Area();
                }
                else if (faceOrArea == "perimeter")
                {
                    Perimeter();
                }
                else if (faceOrArea == "both")
                {
                    AreaAndPerimeter();
                }
                else
                {
                    Console.WriteLine("\nPlease choose for your input one of the options we have presented you in the upper line!\n");
                }
            }
        }

        private void Area()
        {
            area = Math.PI * Math.Pow(radius, 2);
            if (area != 0)
            {
                Console.WriteLine("The area of the circle is: {0:N2}", area);
            }
            else
            {
                Console.WriteLine("Something with your input was wrong!");
                StartAgain();
            }
        }

        private void Perimeter()
        {
            perimeter = 2 * Math.PI * radius;
            if (perimeter != 0)
            {
                Console.WriteLine("The perimeter of the circle is: {0:N2}", perimeter);
            }
            else
            {
                Console.WriteLine("Something with your input was wrong!");
                StartAgain();
            }
        }

        private void AreaAndPerimeter()
        {
            area = Math.PI * Math.Pow(radius, 2);
            perimeter = 2 * Math.PI * radius;
            if (area != 0 && perimeter != 0)
            {
                Console.WriteLine("The area of the circle is: {0:N2}", area);
                Console.WriteLine("The perimeter of the circle is: {0:N2}", perimeter);
            }
            else
            {
                Console.WriteLine("\nSomething with your input was wrong!");
                StartAgain();
            }
        }

        static public void StartAgain()
        {
            Console.Write("Do you want to start from the beginning (Yes / No) ");
            string startAgain = Console.ReadLine().ToLower();
            if (startAgain == "yes")
            {
                Console.Clear();
                Program.Main();
            }
            else if (startAgain == "no")
            {
                Console.WriteLine("Thank you for the time spent.");
            }
            else
            {
                Console.WriteLine("\nPlease choose for your input one of the options we have presented you in the upper line!\n");
                StartAgain();
            }
        }

        private void End(bool end)
        {
            if (end == true)
            {
                Console.WriteLine("\nThank you for your participation!");
            }
        }

        ~Circle()
        {
            bool end = true;
            if (count > 0)
            {
                end = false;
            }
            End(end);
            count++;
        }
    }
}