Lập trình Pascal: viết chương trình tạo hình sao

Program TAO_HINH_A;
Uses Crt;
Var i,j,n: integer;
Begin
Clrscr;
Writeln(' TAO HINH A:');
Writeln('------------------------');
Write('Nhap so dong n=');readln(n);
For i:= 1 to n do
Begin
For j:=1 to i do
Write('* ');
Writeln;
End;
Readln;
End.

Program TAO_HINH_B;
Uses Crt;
Var i,j,n,m: integer;
Begin
Clrscr;
Writeln(' TAO HINH B');
Writeln('----------------------------');
Write('Nhap so dong n= ');readln(n);
For i:= n downto 1 do
Begin
For j:=1 to i do
Write('* ');
Writeln;
End;
Readln;
End.

Program TAO_HINH_C;
Uses Crt;
Var i,j,n,m: integer;
Begin
Clrscr;
Writeln(' TAO HINH C');
Writeln('----------------------------');
Write('Nhap so dong n= ');readln(n);
For i:= 1 to n do
Begin
Gotoxy(n-i+5,i+5);
For j:=1 to 2*i-1 do
Write('*');
Writeln;
End;
Readln;
End.