In geometry, a **square** is a regular quadrilateral. This means that it has four equal sides and four equal angles (90-degree angles, or right angles). It can also be defined as a rectangle in which two adjacent sides have equal length. A square with vertices ABCD would be denoted *ABCD*.

The square is the n=2 case of the families of n-hypercubes and n-orthoplexes.

Read more about Square: Characterizations, Perimeter and Area, Coordinates and Equations, Construction, Properties, Other Facts, Non-Euclidean Geometry, Graphs

### Famous quotes containing the word square:

“If magistrates had true justice, and if physicians had the true art of healing, they would have no occasion for *square* caps; the majesty of these sciences would of itself be venerable enough. But having only imaginary knowledge, they must employ those silly tools that strike the imagination with which they have to deal; and thereby, in fact, they inspire respect.”

—Blaise Pascal (1623–1662)

“Mark you the floore? that *square* & speckled stone,

Which looks so firm and strong,

Is Patience:”

—George Herbert (1593–1633)

“Interpreting the dance: young women in white dancing in a ring can only be virgins; old women in black dancing in a ring can only be witches; but middle-aged women in colors, *square* dancing...?”

—Mason Cooley (b. 1927)