Anxiety Disorder Statistics. Anxiety Disorders affect 18.1 percent of adults in the United States (approximately 40 million adults between the ages of 18 to 54).
Perfect square. Perfect square is an element of algebraic structure which is equal to the square of another element. Square number, a perfect square integer.
The 'perfect acre' is a rectangular area of 43,560 square feet, bounded by sides 660 feet by 66 feet long (660 ft long Ã 66 ft wide), or 220 yards by 22 yards long (220 yd/ long Ã 22 yd wide), or 40 rods by 4 rods long. Thus, an acre is 160 square rods.