Question

The diagonals AC and BD of the convex quadrilateral ABCD with area 28 intersect each other at point O. The lines which are parallel to the diagonal AC come through the midpoints of segments BO and DO . Find the area of the portion of the quadrilateral that is between those lines.

Answer 1

21

Step-by-step explanation (note, the suggested way is not the shortest one):

all the details are in the attached picture.