In geometry, a quadrilateral (four-sided)
plane figure with all sides equal and each
angle a right angle. Its diagonals bisect
each other at right angles. The area A of a
square is the length l of one side multiplied
by itself (A = l x l). Similarly, any
quantity multiplied by itself is also a
square, represented by an exponent (power) of
2; for example, 4 x 4 = 4^2 = 16 and 6.8 x
6.8 = 6.8^2 = 46.24. An algebraic term is
squared by doubling its exponent and squaring
its coefficient if it has one; for example,
(x^2)^2 = x^4 and (6y^3)^2 = 36y^6. A number
that has a whole number as its square root is
known as a perfect square; for example, 25,
144 and 54,756 are perfect squares (with
roots of 5, 12 and 234, respectively).