program laba_1_1_Delphi;

{$APPTYPE CONSOLE}

{$R *.res}

uses
    System.SysUtils;

var
   sideA, sideB, sideC: Real;
   IsCorrect: Boolean;

begin
   Writeln('This program determines if the triangle is equilateral');
   Writeln('Enter side A: ');
   repeat
      try
         Readln(sideA);
         if (sideA > 0) then
            IsCorrect := true
         else
         begin
            IsCorrect := false;
            Writeln('Enter a positive number!');
         end;
      except
         IsCorrect := false;
         Writeln('Enter a positive number!');
      end
   until (IsCorrect);
   Writeln('Enter side B: ');
   repeat
      try
         Readln(sideB);
         if (sideB > 0) then
            IsCorrect := true
         else
         begin
            IsCorrect := false;
            Writeln('Enter a positive number!');
         end;
      except
         IsCorrect := false;
         Writeln('Enter a positive number!');
      end
   until (IsCorrect);
   Writeln('Enter side C: ');
   repeat
      try
         Readln(sideC);
         if (sideC > 0) then
            IsCorrect := true
         else
         begin
            IsCorrect := false;
            Writeln('Enter a positive number!');
         end;
      except
         IsCorrect := false;
         Writeln('Enter a positive number!');
      end
   until (IsCorrect);
   if (sideA + sideB > sideC) and (sideA + sideC > sideB) and
      (sideC + sideB > sideA) then
   begin
      Writeln(' ');
      Writeln('Triangle exists');
      Writeln(' ');
      if (sideA = sideB) and (sideA = sideC) and (sideC = sideB) then
         Writeln('The triangle is equilateral')
      else
         Writeln('The triangle is not equilateral')
   end
   else
      Writeln('Triangle does not exist');
   Writeln(' ');
   Writeln('Press ENTER to exit the program');
   Readln;
end.