54
<|im_start|>system
You are a helpful assistant.<|im_end|>
<|im_start|>user
In the diagram, what is the area of $\triangle ABC$? [asy]
size(5cm);
real xmax = 15; real ymax = 13; real xmin = -3; real ymin = -3;
pair a = (4, 9); pair b = (0, 0); pair c = (12, 0); draw(b--a--c);
draw((xmin, 0)--(xmax, 0), Arrow); label("$x$", (xmax, 0), E);
draw((0, ymin)--(0, ymax), Arrow); label("$y$", (0, ymax), N);
label("$B(0, 0)$", b, SW);
label("$C(12, 0)$", c, S);
label("$A(4, 9)$", a, N);
[/asy]
Please reason step by step, and put your final answer within \boxed{{}}.<|im_end|>
<|im_start|>assistant

user
54
In the diagram, what is the area of $\triangle ABC$? [asy]
size(5cm);
real xmax = 15; real ymax = 13; real xmin = -3; real ymin = -3;
pair a = (4, 9); pair b = (0, 0); pair c = (12, 0); draw(b--a--c);
draw((xmin, 0)--(xmax, 0), Arrow); label("$x$", (xmax, 0), E);
draw((0, ymin)--(0, ymax), Arrow); label("$y$", (0, ymax), N);
label("$B(0, 0)$", b, SW);
label("$C(12, 0)$", c, S);
label("$A(4, 9)$", a, N);
[/asy]
train