In the parallelogram ABCD, EF is the midpoint of AD and BC respectively The intersection of the center line BD and CE of triangle ABC with O, F and G is the midpoint of OB and OC respectively

In the parallelogram ABCD, EF is the midpoint of AD and BC respectively The intersection of the center line BD and CE of triangle ABC with O, F and G is the midpoint of OB and OC respectively

Where is point m, n?
2. Prove: because the center line BD and CE of triangle ABC intersect at point o
So D and E are the midpoint of AC and ab respectively
Because F and G are the midpoint of OB and OC respectively
So de and FG are the median lines of triangle ABC and triangle OBC respectively
So de parallels BC
DE=1/2BC
FG=1/2BC
FG parallel BC
So de parallels FG
DE=FG
So the quadrilateral defg is a parallelogram