A closed planar Quadrilateral with opposite sides of equal lengths and , and with four Right
Angles. The Area of the rectangle is

and its Diagonals are of length

A Square is a degenerate rectangle with .

**References**

Beyer, W. H. (Ed.) *CRC Standard Mathematical Tables, 28th ed.* Boca Raton, FL: CRC Press, p. 122, 1987.

Eppstein, D. ``Rectilinear Geometry.'' http://www.ics.uci.edu/~eppstein/junkyard/rect.html.

© 1996-9

1999-05-25