The ornamental design for a triangularplate for motorframe, as shown and described.
FIG. 1 is a top plan view of the present design a triangular plate for motor frame.
FIG. 2 is a front plan view of the triangular plate for motor frame shown in FIG. 1.
FIG. 3 is a bottom plan view of the triangular plate for motor frame shown in FIG. 1.
FIG. 4 is a bottom perspective view of the triangular plate for motor frame shown in FIG. 1.
FIG. 5 is a top perspective view of the triangular plate for motor frame shown in FIG. 1; and,
FIG. 6 is a top perspective view of the triangular plate for motor frame shown in use, wherein the broken lines are the environment of the triangular plate for motor frame shown in use and form no part of the claimed design.