Since there is no picture, find here-under the conditions that a quadrilateral becomes a parallelogram:
( All are either or)
1- opposite sides should be congruent
2- opposite angles should be congruent
3- opposite sides parallel
4-The sum of 2 adjacent angles to equal 180°
5 the 2 diagonals intersect in their middle
With any of these conditions, if confirmed, you can conclude that the quadrilateral is a parallelogram (By the way a rectangle is a parallelogram with one angle =90°
