As a result of this definition:
- Each pair of opposite sides is of equal length.
- Opposite sides are parallel
- Diagonal are equal
- Adjacent sides are perpendicular
However, the adjacent sides do not need to be of equal length.
- There are many definitions of rectangle, but it seems sensible to use one which ais based on angle properites reather than length or papallesim properties. Definition adapted from http://www.mathsisfun.com/definitions/rectangle.html