triangles topic

Question

in a triangle ABC ,D and E are the points on AB and AC and DE||BC . if length of AB is two times of length AD .then what is the ratio of area of triangle ABC to area of triangle ADE

Answer 1

in two similar triangles, the ratio of their areas is the square of the ratios of their sides

ratio of their sides is AB/AD=2/1

(2/1)^2=4/1