partition of quadrilateral part9@@
@There is a quadrilateral. The length of AP is same the length of BQ. The length of AR is same the length of BS. The ratio of AB is same the ratio of the other sides(BC,CD,DA).

Move points(A,B,C,D,P,R) to find the geometric quality between the red areas and the area of quadrilateral ABCD.

Download CABRIU data (d91) from here.