Is the first stroke of "啟" 点 or 撇 or 横？ The above images seem to indicate different answers.
Under which regional standard are you studying your characters? That'll be your answer.




  Note: 橫 is a 隸書 style, and no region really writes it like that. You'll see Japanese people write 戶 with a 橫 instead, and that's where the influence comes from.