Which side of the armour is hit when an armoured unit is attacked by arty, helos, or planes?

Let's start with artillery. I assume it depends on where the artillery shell falls? If the shell lands next to the unit, then side armour is affected. If it falls in front of the unit, then front armour is affected, etc? But what if you score a direct hit on the armoured unit? Is it then top armour hit? I am of course talking about HE artillery and not cluster artillery which I assume is always top armour...?

Then helo ATGM rockets...do they ever hit top armour? Or is it always front/side/back armour hits?

Same goes for plane ATGM rockets? Always front/side/back armour? What about an HE bomb? If you score a direct hit on an armoured unit with an HE bomb, is that a top armour hit or not?

Thanks in advance.