Rectangle rhymes with:
angle, antifungal, bangle, bengal, bengel, bingel, bingle, bringle, commingle, dangel, dangle, dengel, dingel, dingell, dingle, disentangle, engle, entangle, fangle, fungal, gangl, gingell, hengel, hingle, ingle, intermingle, jangle, jingle, jungle, klingel, krengel, langel, langill, lengel, lingle, mangel, mangle, massingill, mengel, mingle, mongol, mungle, nangle, newfangle, nightengale, pangle, pettengill, pettingill, pingel, pringle, rengel, ringel, ringle, shingle, singel, single, spangle, stangel, stangl, stangle, stengel, strangle, swingle, tangle, tingle, triangle, untangle, vangel, wangle, wettengel, wrangell, wrangle