Answer
64 square feet
Work Step by Step
We know that the area that we want to find is the difference of the areas of the larger and smaller squares. Thus, we obtain:
$$A= s^2 \\ A= 10^2 \\ A= 100$$
$$A=s^2 \\ A=6^2 \\ A=36$$
Now, we find the area of the border:
$$ A= 100 -36 =64$$
