10. As shown in the figure, in the rectangular plate $ABCD$, $AB=3, BC=2$, with the edge $AD$ standing vertically on the ground. There is another vertical rod $MN$ on the ground, such that $NE$ is the perpendicular bisector of $AB$, with $E$ being the foot of the perpendicular, $NE=3$, $MN=5$. There is a point light source at point $M$. Then the area of the projection of the rectangular plate on the ground is $\qquad$.
10. 8 Extend $M D, M C$ to meet the ground at points $P, Q$, connect $N P, N Q, P Q$, extend $N E$ to meet $P Q$ at $F$, connect $M F$ to meet $C D$ at point $G$,
then $G E=2$, and $A B=3, B C=2$,
so $\frac{M N}{G E}=\frac{N F}{E F}$, i.e., $\frac{5}{2}=\frac{E F+3}{E F}$, thus $E F=2$,
similarly, we get $P Q=5$,
therefore, the area of the projection of the rectangular board on the ground $A B Q P$ is $\frac{1}{2} \times(3+5) \times 2=8$.