SOLUTION: Mr. Perez built this circular garden. The inner circle has a diameter of 22 feet. The outer circle has a diameter of 44 feet. The circumference of section B is how many times as

Algebra ->  Circles -> SOLUTION: Mr. Perez built this circular garden. The inner circle has a diameter of 22 feet. The outer circle has a diameter of 44 feet. The circumference of section B is how many times as      Log On


   

Question 72894: Mr. Perez built this circular garden. The inner circle has a diameter of 22 feet. The outer circle has a diameter of 44 feet. The circumference of section B is how many times as long as the circumference of Section A?
What is the area of section B?
Answer by blfaust(5) About Me  (Show Source):
You can put this solution on YOUR website!
Circumference=pi times diameter where pi = 3.1416 C=3.1416*d If section B is larger it will have the diameter of 44 feet. C=3.1416%2A44. C=138.230 ft If section A is the smaller section then it will have a diameter of 22 feet. C=3.1416%2A22. C=69.115 ft Ratio %28138.230%2F69.115%29=2The circumfrence of section B is twice as long as the circumfrence of section A.
I think (without being able to look at your book) section B is the large circle without the little circle. Much like a doughnut. You want to find the Area of the outer section, but not the inner section. To do this, find the Area of the big circle and subtract out the Area of the small circle. Area=pi*radius^2 or A=pi*r^2 Remember radius is half of the diameter. %283.1416%2A22%5E2%29minus %283.1416%2A11%5E2%291520.5344-380.1336Final Area equals 1140.4 feet squared