SOLUTION: in circle O, OB=6 and AB=2. the ratio of the shaded portion to the small circle=?

Algebra ->  Circles -> SOLUTION: in circle O, OB=6 and AB=2. the ratio of the shaded portion to the small circle=?      Log On


   

Question 607213: in circle O, OB=6 and AB=2. the ratio of the shaded portion to the small circle=?
Answer by LisaJ(11) About Me  (Show Source):
You can put this solution on YOUR website!
We need a little more information. Where are A and B in the picture?
Is B on the larger circle and A on the smaller circle?
Is the shaded portion the donut-shaped area between A and B?
IF SO, then the area of the larger circle (radius 6) is pi+%2AR%5E2+=+36+pi
The area of the smaller circle (radius 4) is pi+%2AR%5E2+=+16+pi
The shaded area is the difference: 36+pi+-+16+pi+=+20+pi
...
The ratio of shaded portion to small circle is 20+pi+%2F+16+pi+=+20%2F16+=1.25