16. (3 points) As shown in the figure, the area of rectangle $A D E F$ is 16, the area of triangle $A D B$ is 3, and the area of triangle $A C F$ is 4. Therefore, the area of triangle $A B C$ is $\qquad$
【Solution】Solution: The area of $\triangle A E C$: $16 \div 2-4=4$, the area of $\triangle A B E$: $16 \div 2-3=5$, $B D: B E=3: 5, D E=B D+B E=3+5=8$, the area of $\triangle B C E$: $4 \times \frac{5}{8}=2.5$, the area of $\triangle A B C$: $16-(3+4+2.5)=6.5$; Therefore, the answer is: 6.5.