Modular building block

FIG. 1 is a perspective view, depicting a bottom face in use of a modular building block, facing upward, according to our new design;

FIG. 2 is a front view of the modular building block of FIG. 1 ;

FIG. 3 is rear view of the modular building block of FIG. 1 ;

FIG. 4 is a right side view of the modular building block of FIG. 1 ;

FIG. 5 is a left side view of the modular building block of FIG. 1 ;

FIG. 6 is a top view of the modular building block of FIG. 1 , and depicting the bottom face in use; and,

FIG. 7 is a bottom view of the modular building block of FIG. 1 , and depicting the upper face in use.

The features depicted in broken lines form no part of the claimed design.