# Math Help - Area of walk way and perimeter of pool

1. ## Area of walk way and perimeter of pool

A rectangular pool is twice as long as the it is wide and has a 10 foot walkway surrounding it. If the border has an area of 2800 ft^2 find the perimeter of the pool

so the Length of the border will be 2x+20 and the width be x+10

I have figured out x=40 and the perimeter to equal 240ft? I set my equation to be x^2+10x=1400

Not sure it that is correct?

2. Originally Posted by IDontunderstand
A rectangular pool is twice as long as the it is wide and has a 10 foot walkway surrounding it. If the border has an area of 2800 ft^2 find the perimeter of the pool

so the Length of the border will be 2x+20 and the width be x+10

I have figured out x=40 and the perimeter to equal 240ft? I set my equation to be x^2+10x=1400

Not sure it that is correct?
Hi IDontunderstand,

That's what I got. I used the total area of the pool with the walkway, then subtracted the area of the pool to equal the area of the walkway alone. Like this,

$(2x+20)(x+20)-x(2x)=2800$

$x=40$

The pool is 40 X 80 with a perimeter of 240.