SEAMO 2018 — Paper E — Grade 9–10 Question 24

$ABCD$ is a parallelogram, with $FH\parallel AD$ and $EG\parallel AB$, intersecting at $M$. Areas of $DEMH$ and $BFMG$ are $9$ and $15\,\mathrm{cm}^2$ respectively. Find the area of $\triangle AMC$.