In Euclidean plane geometry, a **rectangle** is a quadrilateral with four right angles. It can also be defined as an equiangular quadrilateral, since equiangular means that all of its angles are equal (360°/4 = 90°). It can also be defined as a parallelogram containing a right angle. A rectangle with four sides of equal length is a square. The term **oblong** is occasionally used to refer to a non-square rectangle.^{[1]}^{[2]}^{[3]} A rectangle with vertices *ABCD* would be denoted as *ABCD*.

The word rectangle comes from the Latin *rectangulus*, which is a combination of *rectus* (as an adjective, right, proper) and *angulus* (angle).

A **crossed rectangle** is a crossed (self-intersecting) quadrilateral which consists of two opposite sides of a rectangle along with the two diagonals.^{[4]} It is a special case of an antiparallelogram, and its angles are not right angles. Other geometries, such as spherical, elliptic, and hyperbolic, have so-called rectangles with opposite sides equal in length and equal angles that are not right angles.

Rectangles are involved in many tiling problems, such as tiling the plane by rectangles or tiling a rectangle by polygons.

A convex quadrilateral is a rectangle if and only if it is any one of the following:^{[5]}^{[6]}

A rectangle is a special case of a parallelogram in which each pair of adjacent sides is perpendicular.

A parallelogram is a special case of a trapezium (known as a trapezoid in North America) in which *both* pairs of opposite sides are parallel and equal in length.

This page was last edited on 20 May 2018, at 15:28 (UTC).

Reference: https://en.wikipedia.org/wiki/Rectangle under CC BY-SA license.

Reference: https://en.wikipedia.org/wiki/Rectangle under CC BY-SA license.

- Euclidean Plane Geometry
- Quadrilateral
- Right Angles
- Square
- Oblong
- Square
- [1]
- [2]
- [3]
- Vertices
- Latin
- Angle
- [4]
- Antiparallelogram
- Spherical
- Elliptic
- Hyperbolic
- Tiling
- Polygons
- Convex
- Quadrilateral
- If And Only If
- [5]
- [6]
- Parallelogram
- Sides
- Perpendicular
- Trapezoid
- Parallel
- Equal
- Length

- Rectangle
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