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.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).
Rectangle
Rectangle
Video: Area of a Rectangle
Type
quadrilateral, parallelogram, orthotope
Edges
and
vertices
4
Schläfli symbol
{ } × { }
Coxeter diagram
Symmetry group
Dihedral (D2), [2], (*22), order 4
Dual polygon
rhombus
Properties
convex, isogonal, cyclic Opposite angles and sides are congruent
Characterizations
Video: Understanding Quadrilaterals - Properties of Rectangles
A convex quadrilateral is a rectangle if and only if it is any one of the following:
a parallelogram with at least one right angle
a parallelogram with diagonals of equal length
a parallelogram ABCD where triangles ABD and DCA are congruent
an equiangular quadrilateral
a quadrilateral with four right angles
a convex quadrilateral with successive sides a, b, c, d whose area is .:fn.1
a convex quadrilateral with successive sides a, b, c, d whose area is
Classification
A rectangle is a special case of both parallelogram and trapezoid. A square is a special case of a rectangle.
Traditional hierarchy
A rectangle is a special case of a parallelogram in which each pair .....