To find the total area of the town of Oak Manor, you can use the formula for the area of a rectangle, which is:
\[ \text{Area} = \text{length} \times \text{width} \]
Here, the length is 4.2 miles and the width is 3.8 miles.
Calculating the area:
\[ \text{Area} = 4.2 , \text{miles} \times 3.8 , \text{miles} = 15.96 , \text{mi}^2 \]
So the total area of Oak Manor is 15.96 mi².