1.

uses crt;

  var A: integer;

begin

clrscr;

  write('Nhap A = '); readln(A);

  if A mod 3 = 0 then write(A, ' chia het cho 3') else write(A, ' khong chia het cho 3');

  readln

end.

2.

uses crt;

  var m: integer;

begin

  clrscr;

  write('Nhap m = '); readln(m);

  if m mod 2 = 0 then write('So vua nhap la so chan!') else write('So vua nhap la so le');

  readln

end.

3.

uses crt;

  var a, h: integer;

            S: real;

begin

  clrscr;

  write('Nhap a = '); readln(a);

  write('Nhap h = '); readln(h);

  S:=a*h/2;

  writeln('Dien tich hinh tam giac do la: ', S:1:0);

  readln

end.

1. 

var a:integer;

begin

write('nhap a:');

readln(a);

if a mod 3=0 then write(a,' chia het cho 3') else write(a,' khong chia het cho 3');

readln;

end.

2.

var m:integer;

begin

write('nhap m:');

readln(m);

if m mod 2=0 then write('so vua nhap la so chan') else write('so vua nhap la so le');

readln;

end.

3.

var a,h:integer;

S:real;

begin

write('nhap a:');

readln(a);

write('nhap h:');

readln(h);

S:=(a*h)/2;

write('dien tich tam giac tuong ung voi do dai tren la ',S:4:2);

readln;

end.