4. Two adjacent sides of a parallelogram are 21 cms and 20 cms. The diagonal joining the end points of these two sides is 29 cms. The area of the parallelogram (in sq.cms) is
10. D and E are points on side AB and AC of ?ABC. DE is parallel to BC. If AD:DB = 2:5 and area of ?ADE is 8 sq cm, what is the ratio of area of ?ADE: area of quadrilateral BDEC?