D. All of the above.
Both the square and parallelogram has 4 sides and 4 straight lines.
Since the square and parallelogram has 4 straight lines, the opposite sides will be parallel.
A trapezoid has the bottom and top line parallel.
It should be a parallelogram, as, since they are parallel, the angles opposite each other will be the same, since 360 degrees makes a whole circle, which is also the whole shape, if the sum of one opposite side is equal to 180degrees, the whole parallelogram will be 360 degrees. So, it should be a parallelogram.
No, i disagree with this statement. A square has parallel lines. But, the whole shape must be the same length, however, in the parallelogram, the length can differ. So, in this case, the angles of the parallelogram can be different. But, the angle of the square remains as 90 degrees.