sentences:  In contrast to the static 46° halo, the shape of a supralateral arc varies with the elevation of the sun.Before the sun reaches 15°, the bases of the arc touch the lateral (oriented sidewise) sides of the 46° halo.As the sun rises from 15° to 27°, the supralateral arc almost overlaps the upper half of the 46° halo, which is why many reported observations of the latter most likely are observations of the former.