If D,E are the mid-points of AB, AC of △ABC and ¯¯¯¯¯¯¯¯¯DE=λ¯¯¯¯¯¯¯¯BC then λ =
D and E are points on the sides AB and AC respectively of a △ABC such that DE || BC and DE divides △ABC into two parts that are equal in area. Find BDAB.