Photorefractive keratectomy. Photorefractive keratectomy (PRK) and laser-assisted sub-epithelial keratectomy (or laser epithelial keratomileusis) (LASEK) are laser eye surgery procedures intended to correct a person's vision, reducing dependency on glasses or contact lenses.
One acre is 43,660 square feet so 10 acres is 435,600 square feet. The area of a square is L 2 where L is the length of a side, so if the shape really is a square . L 2 = 435,600 square feet. so. L = Sqrt(435,600) = 660 feet. Penny
A square mile is defined as 640 acres. A square mile is 5,280 feet x 5,280 feet, for a total of 27,878,400 square feet. Divide that by 640 to get 43,5â¦60 square feet in an acre. An acre is 43,560 square feet.