You can
put this solution on YOUR website!The area of a circular ring is 90
. If the radius of the outer circle forming the ring is 9,
what is the radius of the inner circle of the ring?
(Assume the circles forming the ring have the same center.)
:
Find the total area of the circle
A =
A = 254.469
:
The the area of the small circle: 254.469 - 90 = 164.469
:
Find the radius (r) of the small circle
= 164.469
r =
r = 7.235 is the radius of the small circle
:
:
Check this:
overall area - small circle area
254.469 -
= 90.0
