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 US acre is 1 sq/mi = 640 acres 663,267 x 640 = 424,490,880 acres http://en.wikipedia.org/wiki/Square_mile. According to Wikipedia, the area of Alaska is 663,267 square miles. Since there are 640 acres per square mile, then Alaska covers 424,490,880 acres. * 228 million acres that are part of the federal domain.