Explanation: A) Both square and a parallelogram are four-sided figures. So both are quadrilaterals.
B) In both shapes, the pair of opposite angles that are supplementary. So both are parallel.
C) If a line is drawn perpendicular to 'a', it is also perpendicular to 'b'. (Image Source: http://math.about.com/od/formulas/ss/areaperimeter_2.htm)
Ans: It is a Trapezoid.
Explanation: It cannot be a square, rectangle or a parallelogram as one of the pair of the lines are not equal. Moreover, the pair of opposite angles that are supplementary. So it is more likely to be a Trapezoid.
Explanation: All parallelograms are not squares as squares must have four right-angles and four equal sides.