using System;

public class Program

{

    public static void Main()

    {

        while(true)

    {

        Console.WriteLine("\n\nwhich program you choose");

        Console.WriteLine("1 : Pythagoras's Theoram");

        Console.WriteLine("2 : Extended BMI Calculator with category classification");

        Console.WriteLine("3 : Quadratic equation determinant");

        Console.WriteLine("4 : Cartesian Quadrant Checker");

        int programInput = Convert.ToInt32(Console.ReadLine());

        if (programInput == 1)

        {

            Console.WriteLine("\n1: sqrt programme");

        Console.WriteLine("*****************");

        Console.Write("A*A : ");

        Double a = Convert.ToDouble(Console.ReadLine());

        Console.WriteLine("you entered: " +a);

        Console.Write(" B*B : ");

        double b = Convert.ToDouble(Console.ReadLine());

        Console.WriteLine("you entered:" +b);

        double result = (a*a) + (b*b);

        Console.WriteLine("your result"+result);

        }

        else if (programInput == 2 )

        {

            Console.WriteLine("\n2 : BMI calculator");

        Console.WriteLine("******************");

        Console.Write("input 1 :");

        int firstnumber =Convert.ToInt32 (Console.ReadLine());

        Console.WriteLine("My Weigth :" + firstnumber);

        Console.Write("\ninput2 : ");

        double Secondnumber =Convert.ToDouble(Console.ReadLine());

        Console.WriteLine("My Heigth :" + Secondnumber);

        Double Result = firstnumber / (Secondnumber * Secondnumber) ;

       Console.WriteLine("Your result :" + Result);

        Console.WriteLine("BMI calculation\n");

        Console.Write("result");

        double BMIValue =Convert.ToDouble(Console.ReadLine());

        if ((BMIValue >0) && (BMIValue <16))

        {

            Console.WriteLine("result show :severe thinness");

        }

        else if ((BMIValue ==16) && (BMIValue ==17)) 

        {

            Console.WriteLine("result show:Moderate thinness");

        }

        else if ((BMIValue >17) && (BMIValue <18.5))

        {

            Console.WriteLine("result show:mild thinness");

        }

        else if ((BMIValue >18.5) && (BMIValue <25))

        {

            Console.WriteLine("value show:normal");

        }

        else if ((BMIValue >25) && (BMIValue <30))

        {

            Console.WriteLine("result show :Overweigth");

        }

        else if ((BMIValue >30) && (BMIValue <35))

        {

            Console.WriteLine("result show:Obese class |");

        }

        else if ((BMIValue >35) && (BMIValue <40))

        {

            Console.WriteLine("result show:Obese class ||");

        }

        else if (BMIValue >40) 

        {

            Console.WriteLine("result show :Obese class |||");

        }

        }

    else if (programInput ==3)

    {

        {

        Console.WriteLine("\n3 : Quadratic Equation\n");

        Console.Write(" value a :");

        double inputOne =Convert.ToDouble(Console.ReadLine());

        double a2 = inputOne *inputOne ;

        Console.WriteLine("a^2="+a2);

        Console.Write(" value  b:");

      Double inputTwo =Convert.ToDouble(Console.ReadLine());

        double b2 = inputTwo*inputTwo;

        Console.WriteLine("b^2="+b2);

        Console.Write(" value c :");

        double inputThree =Convert.ToDouble(Console.ReadLine());

       Double c2 = inputThree * inputThree ;

      Console.WriteLine("c^2="+c2);

        double X = (a2) + (b2) + (c2);

        Console.WriteLine("a^2 + b^2 + c^2) = "+X);

        Console.Write("formula is b^2-4ac : ");

        double Y = ((inputTwo*inputTwo)) - ((4) * (inputOne) * (inputThree));

        Console.WriteLine("value :" + Y);

        int answer=Convert.ToInt32(Y);                 

        if (Y ==0)

        {

            Console.WriteLine("result:the curve has 1root");

        }

        else if (Y >0)

        {

            Console.WriteLine("result:the curve have 2root");

        }

        else if (Y <0)

        {

            Console.WriteLine("result:the curve is imaginary root");

        }

        }

    }

    else if (programInput == 4)

        {

            {

             Console.WriteLine("\n4 : Cartesian Quadrant");

        Console.Write("Coordinate X : ");

        int firstnumber =Convert.ToInt32 (Console.ReadLine());

        Console.Write("Coordinate Y : ");

        double secondnumber =Convert.ToDouble(Console.ReadLine());

        if ( firstnumber >= 1 )

        { 

            if (secondnumber >= 1)

            {

                Console.WriteLine("result : Quadrant I");

            }

            else if (secondnumber <= -1)

            {

                Console.WriteLine("result : Quadrant IIII");

            }

            if ( firstnumber <= -1 ) 

        {

            if (secondnumber >= 1 )

            {

                Console.WriteLine("result : Quadrant II");

            }

            else if (secondnumber <= -1 )

            { 

                 Console.WriteLine("result : Quadrant III");

            }

         }

        if ( firstnumber == 0 )

        { 

            if ((secondnumber >=1 ) || (secondnumber <=-1 ))

            {

                Console.WriteLine("result : Coordinate lies on X-axis");

            }

            if (( firstnumber >=1 ) || (firstnumber <=-1 ))

        {

            if (secondnumber ==0 )

            {

                Console.WriteLine("result : Coordinate lies on Y-axis");

            }

        }

        if ( firstnumber == 0 ) 

        { 

            if (secondnumber == 0 )

            {

                Console.WriteLine("result : Origin");

            }

         }

    }

    }

}

}

            Console.ReadLine();

            Console.Clear();

}

}

}

​

​