M is (0,5) N is (4,6)
MN has slope 1/4, BC has slope 2/8= 1/4
Just take the averages of the x coordinates and of the y coordinates to get the midpoints
For M average -1 and 1 to get 0, and 8 and 2 to get 5
slope is the difference in y coordinates divided by the difference in x coordinates ("rise over run")
for MN slope is (6-5)/((4-0) = 1/4
for BC slope is (10-8)/(7--1) = 2/8 = 1/4
if slopes are equal, the lines are parallel