You may mean a quadrilateral (two-dimensional polygon with 4 sides), since a quadrangle is an open space surrounded by buildings on four sides.
You can form an irregular quadrilateral by having 4 different angles, or having at least two sides of unequal length. If two angles are congruent along the same side, you will have a trapezoid (UK trapezium).
A trapezoid
A rhombus for example
It could look like an arrowhead (or delta).
parallelagram http://en.wikipedia.org/wiki/Parallelagram well specifically you would be a rectangle which has parallel sides like a square. a parallelogram can be a square or a rectangle because they all have parallel sides but only squares and rectangles have right angles on all sides. parallelograms have congruent sides which require acute and obtuse angles.
Six parallel sides in pairs? Sounds like a cube.
Cannot show you but it is like a triangle where the top has been chopped off by a line parallel to its base.
Both have four sides comprising two pairs of parallel sides.
Like rectangles, they have two pairs of parallel sides.
Looks like a parallelogram
5 pairs of parallel sides * * * * * The above answer was written by someone who does not know the difference between a decagon (10 sides) and a dodecagon (12 sides). A dodecagon need not have any parallel sides. It can have 1, 2, 3, 4, 5 or 6 pairs. It can have 1, 2, 3 or 4 triplets; 1, 2 or 4 quartets or 2 sextets. It can also have combinations like 2 pairs and 1 triplet.
parallelogram. it looks like: ____ /___/
It looks like a skewed rectangle and has two pairs of parallel sides.