(Geometry) A plane rectangle with four equal sides and four right angles; a four-sided regular polygon; SYN. foursquare.
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).
Also, any quantity multiplied by itself is termed a square, represented by an exponent of power 2; for example, 4 x 4 = 42 = 16 and 6.8 x 6.8 = 6.82 = 46.24.
An algebraic term is squared by doubling its exponent and squaring its coefficient if it has one; for example, (x2)2 = x4 and (6y3)2 = 36y6. 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).