Question 57455
to find the median of the triange you must find the mid point of the base, in this case BC. the mid point is (x1+x2)/2,(y1+y2)/2, that gives you your reference point, lets call it H. 

h=(x1+x2)/2,(y1+y2)/2
h=(-4+2)/2,(1+-6)/2
h=-1,-2.5

now you draw a line from A to H and calculate the mid point of the new line, (x1+x2)/2,(y1+y2)/2 to find the median point J.

J=(x1+x2)/2,(y1+y2)/2
J=(8+-1)/2,(6+-2.5)/2
J=3.5,1.75

I know you can graph these points on your own, so once you do you can also plot the point 3,-4 on your graph. you can see that when you connect the verticies of b, to that point. it  does not form a 90 degree angle, so it is not an altitude of b.