SOLUTION: How do you solve for the area of a shaded region? I have an unshaded circle within a shaded circle. The formula I was given is pi r squared. The numbers given are in the two circle

Question 424940: How do you solve for the area of a shaded region? I have an unshaded circle within a shaded circle. The formula I was given is pi r squared. The numbers given are in the two circles inside the shaded region each have a diameter of 3 and the shaded region is twelve. I tried squaring them and then subtracting. (it says to subtract the shaded region)
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
How do you solve for the area of a shaded region? I have an unshaded circle within a shaded circle. The formula I was given is pi r squared. The numbers given are in the two circles inside the shaded region each have a diameter of 3 and the shaded region is twelve. I tried squaring them and then subtracting. (it says to subtract the shaded region)
-----
Find the area of the larger circle.
A = pi*12^2 = 144pi
-----
Find the area of the inner circle.
a = pi*3^2 = 9pi
----
Subtract the inner circle area from the larger circil area
to find the shaded area.
Area = 144pi-9pi = 135pi sq units.
===============
Cheers,
Stan H.
==============
RELATED QUESTIONS
How do I find the area of a shaded region - of a... (answered by Alan3354)

how do you find the perimeter of a shaded region of a circle the shaded region is 140 (answered by josgarithmetic,Edwin McCravy,josmiceli,AnlytcPhil)

Find the area and perimeter of the shaded region. (answered by scott8148)
how do you find the perimeter of a shaded region of a circle the shaded region is 140 (answered by Fombitz)
what is the formula for finding the area of a shaded region in a circle... (answered by Fombitz)
how do I find the area of the shaded region of 6ft radius 18ft base circle . (answered by Alan3354)
I am not sure how to word this queation but I'll give it a try. I actually have a diagram (answered by stanbon)
I need to find the area of a shaded region in which a rectangle is inside a circle. The... (answered by ankor@dixie-net.com)
Find the area of the shaded region of a circle. The Shaded is 100/360 an... (answered by Mathematicians)