we know that
The area of a rectangle is equal to
where
L is the length side of the rectangle
W is the width side of the rectangle
see the attached figure with letters to better understand the problem
The area of the pool's border is equal to the area of rectangle ABCD minus the area of rectangle EFGH
The formula to calculate the distance between two points is equal to
Step 1
<u>Find the distance AB</u>
Let
substitute the values in the formula
Step 2
<u>Find the distance BC</u>
Let
substitute the values in the formula
Step 3
<u>Find the distance EF</u>
Let
substitute the values in the formula
Step 4
<u>Find the distance FG</u>
Let
substitute the values in the formula
Step 5
<u>Find the area of the pool's border</u>
The area of the pool's border is equal to the area of rectangle ABCD minus the area of rectangle EFGH
<u>Area of the rectangle ABCD</u>
<u>Area of the rectangle EFGH</u>
<u>Area of the pool's border</u>
therefore
<u>the answer is</u>