The ornamental design for a modulartheater, as shown and described.
FIG. 1 is a perspective view of a modular theatre showing my new design;
FIG. 2 is a front elevational view thereof;
FIG. 3 is a side elevational view thereof;
FIG. 4 is a rear elevational view thereof; and,
FIG. 5 is a top plan view thereof.
The broken lines showing the ground line in FIGS. 2-4 illustrate the environment of the claimed design and forms no part thereof. Additional broken lines shown in FIGS. 1, 2, and 5 illustrate portions of the modular theater that form no part of the claimed design.