Determine triangle. Equilateral, isosceles, right-angled or incorrect triangle.

{ TROJUHOL.PAS                                                      }
{ Zo zadanych dlzok stran urci ci je trojuholnik                    }
{ rovnostranny, rovnoramenny, pravouhly, neexistujuci.              }
{                                                                   }
{ Author: Juraj Pupak                                               }
{ Date  : 27.10.2006                           http://www.trsek.com }
 
program Trojuholnik;
uses crt;
var
  a,b,c : integer;
 
begin
 clrscr;
 writeln('Zadaj strany trojuholnika a,b,c');
 readln(a);
 readln(b);
 readln(c);
 clrscr;
 
 IF (a = b) and (b = c) and (a = c) THEN
  begin
    writeln('Rovnostranny');
  end;
 
 IF ((a = b) and (a <> c)) 
 or ((a = c) and (a <> b))
 or ((b = c) and (a <> c)) THEN
  begin
    writeln('Rovnoramenny');
  end;
 
 IF ((a * a) + (b * b) = (c * c))
 or ((a * a) + (c * c) = (b * b))
 or ((b * b) + (c * c) = (a * a)) THEN
  begin
    writeln('Pravouhly');
  end;
 
 IF (a + b < c) or (a + c < b) or (b + c < a) THEN
  begin
    writeln('Neexistuje');
  end;
 readln;
end.