The ornamental design for a triangularcosmeticsbox, as shown and described.
FIG. 1 is a rear perspective view of the triangular cosmetics box showing my new design, with transparent windows at two rectangular panels; and,
FIG. 2 is a front perspective view thereof.
The body of the triangular cosmetics box is a hollow triangular prism, closed at both ends by plane triangular faces parallel with each other. Each of the rectangular panels forming the sides of the triangular box and one of the parallel sides has imprinted designs on them in contrasting appearance.