Yes you can. The quadrilateral that you would get is called parallelogram. It has 2 paris of parallel lines. and 2 pairs of equal angles. one pair is angles that are less than 90 degrees and other one is where 2 angles are greater than 90 degrees each. Therefore there isnt any right angle there and you got yourself quadrilateral. of these 2 parallel lines are of equal lenght than you get something called rhombus.