jmc

Since $E$ is the midpoint of $AC$, the area of triangle $BCE$ is half the area of triangle $ABC$, or $144/2=72$.



Since $GN$ is parallel to $BC$, triangles $ENG$ and $ECB$ are similar. Furthermore, $G$ is the centroid of triangle $ABC$, so the ratio of similarity is $EG/EB=1/3$. Therefore, the area of triangle $ENG$ is $72\cdot (1/3{)}^2=\boxed{8}$.