Answer:
18.
Explanation:
4yd is on the bottom.
9yd is on the left.
13yd is on the right.
The area for a triangle is
We add the numbers into the formula.
![(1)/(2) *4*9 = 18.](https://img.qammunity.org/2022/formulas/mathematics/high-school/2wfd2ntshgr961a7gpo9249rj632rghfxt.png)
We do not use 13, because it is only going from one corner to the opposite corner. So, the answer is 18.
Hope this helped!