https://en.wikipedia.org/wiki/Spaced_armour
not that hard to find
Exactly. Spaced armor is specifically used to minimize the damage of HEAT shells. Sandbags might also be helpful (although slightly), even if the trajectory and direction of the shell is changed by sandbag, that's enough. They were also used to reduce ricocheted bullets. A battle is a shitstorm of bullets coming from different directions which might ricochet and hit supporting infantry.