Jan Myers creates movement in her quilts through repetition and alternation of colors. Only after looking closely do we see that, like the keys on a piano, every square in the quilt moves up a note in value. Laid over the diagonal "cylinders" of graduated color is a beige grid that appears lighter or darker, depending on the colors behind it. Our eye races across this quilt, up and down and over the rolling cylinders.
I believe the correct answer to this is:
groin vaults are constructed by placing barrel vaults at right angles to cover a sqaure space known as a bay.
Hope this helps :)
Adobe Photoshop and Picsart is the best image editing.
Ii think its an intern course. hope it helps :D