Answer:
KL // MN & KN // LM
Step-by-step explanation:
One property of parallelogram is every two opposite sides are parallel to each other and if a two lines (sides) are parallel so they must have the same slope.
In the parallelogram KLMN:
using the slope formula = y2-y1/x2-x1
plug the numbers: KL // MN & KN // LM so KLMN is a parallelogram
