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
There are 43,560 square feet in one acre.   An acre is a unit of area. 640 acres equal a square mile. Hence, it is 1/640 of a square mile. Since a square mile contains 2 â¦ 7,878,400 square feet, an acre is 27,878,400 divided by 640, which is 43,560 square feet. Remember: an acre can be converted to SQUARE feet, not plain (linear) feet. Square feet and feet are not the same units.