math
posted by audrey on .
There is a water reservoir beneath a circular garden to supply a fountain in the garden. The reservoir has a 26inch diameter. The garden has a 12foot diameter. How much of the garden doesn't contain the water reservoir?
I have no idea how to do this please explain!!!

Find the areas of both circles. I suggest you use 72 inches instead for the radius of the garden.
A = pi * r^2 
i am still confused so you find the areas of both circles, but whats the formula? pi times r times 2? please help me!!!!!

wait so after you find the areas you subtract the reservoir from the garden to get the answer?

A  pi * radius squared
Yes  subtract the area of the reservoir from the area of the garden. 
The answer is417.62 after finding the area of both objects and subtracting them