CodeList_6_CSharp.cs

bool isTriangle = true;
char OK = 'Y';
float a,b,c;
do
   {
                Console.WriteLine("Nhap a = ");
                a = float.Parse(Console.ReadLine());
                Console.WriteLine("Nhap b = ");
                b = float.Parse(Console.ReadLine());
                Console.WriteLine("Nhap c = ");
                c = float.Parse(Console.ReadLine());
                if(a<=0 || b<=0 || c<=0)
                    isTriangle = false;
                if((a + b <= c) || (a + c <= b) || (b + c <= a))
                    isTriangle = false;
                if(isTriangle)
                    Console.WriteLine("Day la tam giac");
                else
                    Console.WriteLine("Day khong phai la tam giac");
                isTriangle = true;
               Console.WriteLine("Ban muon tiep tuc khong?(Y/N)");
                OK = Console.ReadKey().KeyChar;
  
} while(OK != 'N');
Console.ReadKey();