As shown in the figure below, $\triangle DEF$ is a triangle inside $\triangle ABC$.
Such that the area of $\triangle ABC$ is two times the area of $\triangle DEF$.
I have no idea here. My first thought is that we could make parallel lines on $D, E, F$, though that would split $\triangle DEF$ into parts, which isn't ideal.
Another idea was similar triangles, due to the fact that the sides are proportional. But the angles don't seem to be the same.