uses crt;
var a,b,c: real;
begin
clrscr;
write('nhap a: ');
readln(a);
write('nhap b: ');
readln(b);
write('nhap c: ');
readln(c);
while (a+b<c) or (a=0) or (b=0) or (c=0) do
begin
write('day khong phai la tam giac');
write('nhap lai a: ');
readln(a);
write('nhap lai b: ');
readln(b);
write('nhap lai c: ');
readln(c);
end;
if (a=b) or (b=c) or (a=c) then write('day la tam giac can')
else if (sqr(a)=sqr(b)+sqr(c)) or (sqr(b)=sqr(a)+sqr(c)) or (sqr(c)=sqr(b)+sqr(a)) then
write('day la tam giac vuong')
else write('day la tam giac thuong');
readln
end.
