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:

“Rationalists, wearing *square* hats,

Think, in *square* rooms,

Looking at the floor,

Looking at the ceiling.

They confine themselves

To right-angled triangles.”

—Wallace Stevens (1879–1955)

“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)

“This house was designed and constructed with the freedom of stroke of a forester’s axe, without other compass and *square* than Nature uses.”

—Henry David Thoreau (1817–1862)