Answer:
predella
Step-by-step explanation:
Otto portrays a soldier in the predella, which is lying below the tree paintings that together make "The War", this is called a Triptych, a oil painting composed of 3 parts with the predella.
He based his composition on the Renaissance formula, with the inclusion of the predella, a strength to the horros of war is then added.
Otto Dix is known for his anti war portrayals, as he was a witness to the horror caused by World War I.
The painting can be interpreted as a gray view of a battle that often solved little as frontlines with trenches gained little at the cost of huge amounts of soldiers.