Words That Rhyme With "Pentagonal" :
3 syllables:
acronal, agonal, cantonal, factional, fractional, national, passional, patronal, rational, trigonal
4 syllables:
binational, decagonal, diaconal, diagonal, heptagonal, hexagonal, irrational, isogonal, octagonal, orthogonal, polygonal, tetragonal, transnational, unnational
5 syllables:
dodecagonal, international, intranational, multinational, subdiaconal, supernational, superrational, supranational, suprarational