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.
Definition: A square is a quadrilateral with all four angles right angles and all four sides of the same length. So a square is a special kind of rectangle, it is one where all the sides have the same length. Thus every square is a rectangle because it is a quadrilateral with all four angles right angles. However not every rectangle is a square, to be a square its sides must have the same length. Penny.