Answer:
9 square kilometers
Explanation:
Let's round the width to 2.0 kilometers, and round the length to 4.5 kilometers.
We know that area is length times width, so
A = lw
A = 2.0*4.5
A = 9.0 square kilometers
If we do this on the calculator, it's around 9.36 square kilometers, so our estimate was good.