SOLUTION: Hi, I have a question about concentric circles. I am building a circular rug 9 feet across. I have lengths of fabric 46in long and 1in wide. If I coil the lengths of fabric to cove

Algebra ->  Circles -> SOLUTION: Hi, I have a question about concentric circles. I am building a circular rug 9 feet across. I have lengths of fabric 46in long and 1in wide. If I coil the lengths of fabric to cove      Log On


   



Question 911771: Hi, I have a question about concentric circles. I am building a circular rug 9 feet across. I have lengths of fabric 46in long and 1in wide. If I coil the lengths of fabric to cover the area of the circle, how many lengths of fabric do I need? Is there a formula?
Answer by ichigo449(30) About Me  (Show Source):
You can put this solution on YOUR website!
You're total circle has area pi*81/4 feet and your fabric has length 46 so can form a circle of circumference 46 or area 530in, as area is C^2/4pi, as its boundary is 1 inch wide. This converts to 44.17 feet and your area total is 63.6 so the annulus between is 63.6-44.17 = 19.4 which you have too much fabric for. Hope this was helpful.