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.
Square. A square is a regular quadrilateral. All of its angles are equal (90Â°). All of its sides are of equal length. Opposite sides are parallel. The diagonals bisect each other at 90Â°. The diagonals are equal in length. It has 4 lines of symmetry. Order of rotational symmetry: 4.