Answer:
AD║BC
AB║DC
Step-by-step explanation:
The vertices of parallelogram are A(0,0), B(b,0), C(2j,2k) and D(2j-b,2k).
If a line passes though two points, then the slope of the line is
Using this formula the slope of AD is
Using the above formula the slope of BC is
The side AD is parallel to side BC because the slope of two parallel lines are same.
AD║BC
The slope of AB is
The slope of DC is
The side AB is parallel to side DC because the slope of two parallel lines are same.
AB║DC
Therefore the required answers are , , ,, AD║BC, AB║DC.