4/

var a,b,c:real;

begin

writeln('Nhap a:'); Readln(a);

writeln('Nhap b:'); Readln(b);

writeln('Nhap c:'); Readln(c);

if (a=b and b=c or b=c and c=a) then writeln('La tam giac deu');

else writeln('Khong phai la tam giac deu');

Readln

End.

5/

var a,b,c:real;

begin

writeln('Nhap a:'); Readln(a);

writeln('Nhap b:'); Readln(b);

writeln('Nhap c:'); Readln(c);

if (a=b or b=c or a=c) then writeln('La tam giac can');

else writeln('Khong phai la tam giac can');

Readln

End.

6/

var a,b,c:real;

begin

writeln('Nhap a:'); Readln(a);

writeln('Nhap b:'); Readln(b);

writeln('Nhap c:'); Readln(c);

if (a*a=b*b+c*c or b*b=c*c+a*a or c*c=b*b+a*a) then writeln('La tam giac vuong');

else writeln('Khong phai la tam giac vuong');

Readln

End.