SOLUTION: Two concentric circles are drawn so that the shaded area is equal to the unshaded area. The radius of the outer circle is 8 cm. Find the difference in the radii of the two circles.

Algebra.Com
Question 1208982: Two concentric circles are drawn so that the shaded area is equal to the unshaded area. The radius of the outer circle is 8 cm. Find the difference in the radii of the two circles.
Answer by ikleyn(52782)   (Show Source): You can put this solution on YOUR website!
.
Two concentric circles are drawn so that the shaded area is equal to the unshaded area.
The radius of the outer circle is 8 cm. Find the difference in the radii of the two circles.
~~~~~~~~~~~~~~~~~~ 

outer circle   inner circle   shaded/unshaded
  area            area           area
 
        -       =   .


From this equation

     =  + ,

    64 = ,

     = 64/2 = 32,

    r =  = 


The difference in the radii is   = 2.343146  cm  (rounded).     ANSWER

Solved.



RELATED QUESTIONS

Two concentric circles are drawn so that the inner circle is shaded. The shaded area is... (answered by josgarithmetic)
Two concentric circles are drawn so that the shaded area is equal to the unshaded area.... (answered by josgarithmetic)
Three concentric circles are drawn such that the area of the smallest circle is equal to... (answered by Boreal)
[ Find the area enclosed between two concentric circles of radii 6.3 cm and 8.4 cm. A... (answered by TimothyLamb)
An archery target is constructed of four concentric circles such that the area of the... (answered by KMST)
An archery target is constructed of five concentric circles such that the area of the... (answered by greenestamps)
The circles are concentric. The inner circle is shaded. The cord is tangent to the inner... (answered by MathLover1,pedjajov)
given are two centric circles with outer circle having a radius of 10cm. if the area of... (answered by ewatrrr)
Diagram of circle with outer edge shaded. The outer circle has diameter 8 inches. The... (answered by josgarithmetic,MathTherapy)