SEAMO 2026 — Paper B — SET 3 — Organizer self-practice Question 9

In the figure, lines $AC$ and $BD$ divide quadrilateral $ABCD$ into four triangles. The areas of $\triangle ADO$, $\triangle CDO$, $\triangle ABO$ are $2$, $4$ and $3$ cm$^2$, respectively. Find the area of $ABCD$ in cm$^2$.