Quadrilateral-meaning: A plane having four sides and four angles.




3-6.gif
quadrilaterals.gif
quadrilaterals.gif


The Rectangle

Rectangle
Rectangle



external image quadrilateral-right-key.gif
means "right angle"
external image quadrilateral-equal-key.gifandexternal image quadrilateral-equal-key2.gif
show equal sides


A rectangle is a four-sided shape where every angle is a right angle (90°).
Also opposite sides are parallel and of equal length.

The Rhombus

Rhombus
Rhombus

A rhombus is a four-sided shape where all sides have equal length.
Also opposite sides are parallel and opposite angles are equal.
Another interesting thing is that the diagonals (dashed lines in second figure) of a rhombus bisect each other at right angles.

Complex Quadrilaterals

Oh Yes! when two sides cross over, you call it a "Complex" or "Self-Intersecting" quadrilateral like these:
Complex Quadrilaterals
Complex Quadrilaterals

They still have 4 sides, but two sides cross over.

quadrilateral-class.gif
quadrilateral-class.gif

Quiz on Quadrilaterals

http://www.interactivestuff.org/match/maker.phtml?featured=1&id=24 Matching Game on Quadrilaterals


game number two : http://teams.lacoe.edu/documentation/classrooms/amy/geometry/6-8/activities/quad_quest/quad_quest.html