a/
Program baitap;
Uses crt;
Begin
Clrscr;
Writeln('Dien tich HCN:', 4*5);
Writeln('Chu vi HCN:', (4+5)*2);
Readln
End.
b/
Program baitap;
Uses crt;
Var a,b:real;
Begin
Clrscr;
Write('Nhap chieu dai va chieu rong:');
Readln(a,b);
Writeln('Dien tich HCN:', a*b);
Writeln('Chu vi HCN:', (a+b)*2);
Readln
End.