Answer:
54
![m^2](https://img.qammunity.org/2021/formulas/mathematics/middle-school/xjkldlqcjzmqogeuslgcfj7qyb3ywp3z5v.png)
Explanation:
To find the area of a triangle use the formula a = 1/2bh
The altitude is the same as height so we can substitute 12 for h and 9 for b
Now the equation will become
a = 1/2 · 9 · 12
When you multiply it, it become 108/2 = a simplified to a = 54