Rectangle
From Latin: rectus "right" + angle
A 4-sided polygon with opposite sides parallel and all internal angles are 90°
Try this Drag the orange dots on each vertex to reshape the rectangle.
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The rectangle, like the square, is one of the most commonly known quadrilaterals. It is defined as having opposite sides parallel and its corner angles all right angles (90°) From this it follows that the opposite sides will always be the same length. Adjust the rectangle above and satisfy yourself that this is so.

Since it is also a specific case of a parallelogram , like a parallelogram, its diagonals bisect each other. In a rectangle the diagonals are the same length.

A rectangle can be classified in more than one way, for example a square is a special case of a rectangle. It is also a special case of a parallelogram (but where the angles are fixed at 90°)

See also:
Area of a rectangle
Perimeter of a rectangle
Golden rectangle

Related polygon topics

General

Types of polygon

Area of various polygon types

Perimeter of various polygon types

Angles associated with polygons

Named polygons