Well, the slope for each side is simple.
All you have to do to remember slope is rise over run.
So for example:
For Vertices E and F the Slope would be 3/9
For Vertices G to H the slope would be 3/9
For vertices G to F the slope would be 6/2
For vertices H to E the slope would be 6/2
What do you notice about slopes on opposite sides?
Answer:
( H to E,and G to F) Have the same slope
(And G to H and E to F.) Have the same slope.
What do you notice about slopes of adjacent lines?
adjacent means adjoining or next to. So can you figure this question out? Using the information above?