using System;

/* DO NOT USE CONSOLE.WRITELINE() OUTSIDE OF MAIN */

public class Program

{

    public static void Main()

{ 

        Console.WriteLine ("What do you want to do?\n");

             Console.WriteLine 

("\tA:getHypotenuse()\n\tB:isIsosceles()\n\tC:isEquilateral()\n\tD:getAngle()\n\tE:getArea()\n\tF:getPerimeter()\n");

        string choice = Console.ReadLine().ToUpper();

        double a;

        double b;

        double c; 

        double tBase;

        double tHeight;

        double angle;

        double angle1;

        double angle2;

        switch (choice) 

        { 

            case "A":

                Console.WriteLine("Enter length of side a");

                a = Double.Parse(Console.ReadLine());

                Console.WriteLine("Enter length of side b");

                b = Double.Parse(Console.ReadLine());

                Console.WriteLine(getHypotenuse(a,b));

                break;

                case "B":

                Console.WriteLine("Enter length of side a");

                a = Double.Parse(Console.ReadLine());

                Console.WriteLine("Enter length of side b");

                b = Double.Parse(Console.ReadLine());

                Console.WriteLine("Enter legth of side c");

                c = Double.Parse(Console.ReadLine());

                Console.WriteLine(getIsosceles(true,a,b,c));

                break;

            case "C":

                Console.WriteLine("Enter length of side a");

                a = Double.Parse(Console.ReadLine());

                Console.WriteLine("Enter length of side b");

                b = Double.Parse(Console.ReadLine());

                Console.WriteLine("Enter legth of side c");

                c = Double.Parse(Console.ReadLine());

                Console.WriteLine(getEquilateral(true,a,b,c));

                break;

            case "D": 

                Console.WriteLine("Enter angle a");

                angle1 = Double.Parse(Console.ReadLine());

                Console.WriteLine("Enter angle b");

                angle2 = Double.Parse(Console.ReadLine());

                Console.WriteLine(getAngle(angle1,angle2));

                break;

            case "E": 

                Console.WriteLine("Enter length of side a");

                a = Double.Parse(Console.ReadLine());

                Console.WriteLine("Enter length of side b");

                b = Double.Parse(Console.ReadLine());

                Console.WriteLine(getArea(a,b));

                break;

            case "F": 

                Console.WriteLine("Enter length of side a");

                a = Double.Parse(Console.ReadLine());

                Console.WriteLine("Enter length of side b");

                b = Double.Parse(Console.ReadLine());

                Console.WriteLine("Enter legth of side c");

                c = Double.Parse(Console.ReadLine());

                Console.WriteLine(getPerimeter(a,b,c));

                break;

            default:

                Console.WriteLine("Please try again");

                break;

        }//SWITCH 

    }//Main

    double a;

    double b; 

    double c;

    static double getPerimeter(double a, double b, double c){

        double perimeter = a + b + c;

        return perimeter;

    } 

    static double getArea(double tBase, double tHeight){

        double area = 0.5 * tBase * tHeight;

        return area;

    }  

    static double getAngle(double angle1, double angle2){

        double angle = 180 - angle1 - angle2;

        return angle;

    } 

    static bool getEquilateral(bool equilateral, double a, double b, double c){

        if(a==b && a==c && b==c){

        equilateral = true; 

        }

        else{

        equilateral = false;    

        }

        return equilateral;

    } 

    static bool getIsosceles(bool isosceles, double a, double b, double c){

            if ( a==b || c==a|| b==c){

        isosceles = true;   

        }

        else{

         isosceles = false;

        }

        return isosceles;

    }

    static double getHypotenuse(double a, double b){

        double hypotenuse = Math.Sqrt((a*a)+(b*b));

        return hypotenuse;

    }

}