Armchair

FIG. 1 is a front, left side, top perspective view of an armchair embodying my new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a left side view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is bottom view thereof.

The broken lines are for the purpose of illustrating portions of the armchair and form no part of the claimed design.