D and E are point on the sides AB and AC respectively of a ABC such that DE || BC and divides ABC into two parts, equal in area.

Question

D and E are point on the sides AB and AC respectively of a Δ ABC such that DE || BC and divides  ΔABC into two parts, equal in area. Find BD/ AB.

Answer 1

We have 

area (ΔABC) = area (trapezium BCED)