câu 1:

program ct;

uses crt;

var S,i,n:integer;

begin

clrscr;

  write('nhap n:=');readln(n);

    S:=0;

       for i:=1 to n do S:=S+i;

     writeln('tong la:',S);

readln

end.

câu 2:

program ct;

uses crt;

var P,a,b:integer;

begin

clrscr;

   write('nhap chieu dai:=');readln(a);

   write('nhap chieu rong:=');readln(b);

 P:=(a+b)*2;

   writeln('chi vi hinh chu nhat la:',P);

readln

end.

Bài 1

program Tinh_tong;

uses crt;

var A,n,i: integer;

begin

 clrscr;

 wrietln('nhap so n');readln(n);

 A:=0; i:=0;

 while i<=n do begin A:=A+1; i:=i+1 end;

 readln;

end.

bài 2

    program Chu_vi_hcn;

    uses crt;

   var a,b,cv: integer;

   begin

       clrscr;

       wrieln('Nhap chieu dai a='); readln(a);

       wrietln('Nhap chieu rong b=');readln(b);

       cv:=(a+b)*2;

       writeln('Chu vi hcn la:'cv);

      readln;

end.