It can, but not necessarily. The term quadrilateralrefers to any 4-sided polygon. This does not give you any information on the lengths or equalities of any sides or angles.
The subgroup of quadrilaterals that has equal opposite sides (because there are two sets of parallel sides) is a parallelogram.
rhombus. The rhombus is a quadrilateral with all sides equal in length. It is also a parallelogram, so opposite sides are parallel and equal in length, and opposite angles are equal.
It is not possible for a quadrilateral in Euclidean plane geometry to have no equal angles and still have its opposite sides parallel.It's possible for a quadrilateral to have no equal angles and two of its sides parallel (opposite ones, obviously; adjacent sides can't possibly be parallel). That would be a trapezoid.
A parallelogram.
They are equal and parallel.
Equal and parallel
rhombus. The rhombus is a quadrilateral with all sides equal in length. It is also a parallelogram, so opposite sides are parallel and equal in length, and opposite angles are equal.
A parallelogram has opposite sides and angles congruent which means of equal measure.
It is not possible for a quadrilateral in Euclidean plane geometry to have no equal angles and still have its opposite sides parallel.It's possible for a quadrilateral to have no equal angles and two of its sides parallel (opposite ones, obviously; adjacent sides can't possibly be parallel). That would be a trapezoid.
Parallogram
Rectangle Parallelogram
A parallelogram.
They are equal and parallel.
Equal and parallel
A general quadrilateral.
If a set of equal sides are adjacent, then the quadrilateral is a "kite" shape. If a set of equal sides are opposite, then the quadrilateral is a parallelogram.
rectangle
That quadrilateral is known as a 'parallelogram'.