Quadrilaterals There are a total of eight kind of polygons classified as a quadrilateral. All quadrilaterals are closed four-sided figures.

4 right angles
All angles and sides are congruent
2 sets of parallel lines

Always parallelogram
Only regular quadrilateral
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4 right angles
2 sets of parallel lines (opposite)
2 sets of congruent lines (opposite)
Always Parallelogram
Never kite

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Consecutive angles=180degrees
2 sets of congruent sides
Opposite sides are parallel and congruent
Congruent opposite angles
Diagonals bisect
Sometimes square
Sometimes rectangle
characteristics of a parallelogram

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1 set of parallel lines
Never parallelogram
Parallel sides are called bases
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The top of this table is an example of a trapezoid
The top of this table is an example of a trapezoid

2 sets of parallel lines (opposite)
Similar to parallelogram
All sides are congruent
Opposite congruent angles
Sometimes a square
Diagonals bisect and are perpendicular
Always parallelogram
characteristics of a rhombus
external image rhombus3.gifexternal image Rhombus.png

2 sets of congruent adjacent sides
No parallel lines
Diagonals bisect and are perpendicular
One set of opposite congruent angles
2 90degree angles
1 pair of opposite angles is congruent (ones that are between the sides of unequal length
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Isosceles Trapezoid
2 congruent lines (outside)
One set of parallel lines
Base angles are congruent
Diagonals are congruent
Opposite angles=180degrees
external image Drhom.gifexternal image isotrap.gif

Irregular Quadrilateral
Does not have any special properties