Which of the following statements about trapezoids is  true?                 a.  opposite angles are congruent.      b.  opposite sides are congruent.      c.  both pairs of opposite sides are parallel.      d.  one pair of opposite sides is parallel.

    D one pair of opposite sides is parallel is the answer because trapezoids are another pair angled towards each and if  you follow long enough they will intersect. A couldn't be true because if ALL the angles are corresponding angles you would need two pairs of parallel lines. B isn't correct because the sides would need to be parallel for that too. C well you've already proved they don't have two pairs of parallel lines.

Hope this helps :)

2 is the final ! : )