two squares part3@@
There is two squares.The red square is on the black square.
Point E and F and G and H are the mid points.

When ponit P move on the black square, how do the mid points(E,F,G,H) move?
@You can also move points (A,B,C,D,O,P) on CABRI.

Download CABRIU data (d42) from here.