The applet below contains a quadrilateral that ALWAYS remains a parallelogram. The purpose of this applet is to help you understand many of the geometric properties a parallelogram has. Some of these properties are unique and only hold true for a parallelogram (and not just any quadrilateral). The questions you need to answer are displayed below this applet.
Are opposite sides of a parallelogram congruent?
Are opposite angles of a parallelogram congruent?
Do the diagonals of a parallelogram bisect each other?
Does a diagonal of a parallelogram bisect a pair of opposite angles? If so, how many do?
Are the diagonals of a parallelogram perpendicular?
Are the diagonals of a parallelogram congruent?
Does either diagonal of a parallelogram serve as a line of symmetry? If so, how many?