Let be a plane convex body, and let be the Euclidean length of a longest chord of parallel to the segment in . By the relative length of in a convex body , we mean the ratio of the Euclidean length of to . We say that a side of a convex -gon is relatively short if the relative length of is not greater than the relative length of a side of the regular -gon. In this article, we provide a significant sufficient condition for a convex hexagon to have a relatively short side.