A 270° counterclockwise rotation leads to this transformation:
(x,y) → (y, - x)
So, we have
original point new point
J (-6,2) → J' (2,6)
K (-4,6) → K' (6,4)
L (-3,3) → L' (3,3)
M (-5,-1) → M' (-1,5)
So, you have the points J', K', L', and M' that define the new parallelogram.
Answer: The coordinates of the endpoints of the side congruent to side KL are the coordinates of K' and L' which are (6,4) and (3,3).
