Both pairs of opposite sides need to be congruent (the same length).
A rhombus (4 congruent sides, diagonals perpendicular)that is not also a square (no right angles), andis also a parallelogram (opposite sides parallel and congruent, opposite angles congruent). It is also a quadrilateral, which has 4 sides.
An octagon has 8 sides and a quadrilateral has 4 sides.An octagon has 8 - 4 = 4 more sides than a quadrilateral.
a quadrilateral has 4 sides a hexagon has 6 sides so it's 6/4=1.5
A rectangle or a square.
square, rectangle, rhombus...
Then, the opposite sides are congruent.
If a quadrilateral has two pairs of opposite congruent sides, then the quadrilateral is a parallelogram.
A quadrilateral is a polygon with four sides. A parallelogram is a quadrilateral in which the opposite sides are parallel.
A quadrilateral with both pairs of opposite sides congruent is a parallelogram.