Question

9 mi, 8 mi, square miles

Explanation:

Step1: Recall triangle area formula

The area of a triangle is $\frac{1}{2} \times \text{base} \times \text{height}$.

Step2: Substitute given values

Here, base $= 8$ mi, height $= 9$ mi.
$\text{Area} = \frac{1}{2} \times 8 \times 9$

Step3: Calculate the result

First compute $8 \times 9 = 72$, then $\frac{1}{2} \times 72 = 36$.

Answer:

36 square miles