Triangular division

In a triangular organization, the division's main body is composed of three regimental maneuver elements.

These regiments may be controlled by a brigade headquarters (more typical in World War I) or directly subordinated to the division commander.

After World War II, this structure was retained until the "Pentomic Era" described above.

Soviet Army divisions during World War II were generally triangular, with three subordinate regiments.

In combat operations, however, the fourth regiment could be divided among the other three to create three combined arms formations essentially the same as a brigade.

Triangular Division example: 1942 US Infantry Division. The Brigades of the Square division have been removed, and there are three Regiments directly under Divisional control
Square Division example: 1940 US Infantry Division. On the far left can be seen two Brigades of two Regiments each