Synonyms for Perimeter:

n.

barbed wire, barricade, cattle guard, barrier, chicken wire, chain-link fence, fencing, barricade tape, balustrade. edging. circumference, border (noun)
margin, outline, limit, fringe, edge, ambit, boundary, verge, periphery, compass, brink, brim.
edge (noun)
precipice, curb, outline, periphery, tip, fence, extremity, border, fringe, frontier limit, rim, coast, boundary, side, margin, brink, sharpness, ring, edge, brim.
margin (noun)
study at circumference.
outline (noun)
representation, delineation, drawing, contour, framework, tracing, form, limit, skeleton, silhouette, figure, circumference, profile, girth, configuration, plan, sketch, wire frame, frame.

Other synonyms:

ambit, hypotenuse, edging. compass, verge, cusp. sector. face. corner. Other relevant words:
face, compass, ambit, edging, hypotenuse, sector, corner.