6. 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?
9. The co-ordinates of the centroid of a triangle ABC are (2 , 2). What are the co-ordinates of vertex C if co-ordinates of A and B are (7 , -1) and (1 , 2) respectively?