In the diagram, what is the area of $\triangle A B C$ ?
(A) 36
(B) 54
(C) 108
(D) 72
(E) 48

![](https://cdn.mathpix.com/cropped/2024_04_20_6ed09463f225f8ba1f07g-098.jpg?height=350&width=444&top_left_y=2118&top_left_x=1247)
We think of $B C$ as the base of $\triangle A B C$. Its length is 12 .

Since the $y$-coordinate of $A$ is 9 , then the height of $\triangle A B C$ from base $B C$ is 9 .

Therefore, the area of $\triangle A B C$ is $\frac{1}{2}(12)(9)=54$.

ANSWER: (B)