Here is the triangle:  



A median is a line segment drawn from the vertex of a triangle to
the midpoint of the opposite side.  Since there are three vertices
of a triangle, and three sides, there are THREE medians, not just one.

Here is the median from J to KL:



Here is the median from K to JL



Here is the median from L to JK.



Now, post your problem again, this time be sure to specify exactly
what you want to find.  Do you want to find the length of the three
medians? the length of just one of them? the endpoints of the medians?
Maybe you want to know where all three medians intersect, the centroid.



They all three intersect in one point, called the centroid, or center of
gravity. If you mad the triangle out of heavy cardboard, then the centroid is
the point at which the triangle would just balance if you balanced it on the 
tip of a pencil. 

To find the centroid we just average up the coordinates of the triangle,

(,) = (,)

Post again, telling us exactly what you are to find.

Edwin