**A ring’s a right cylinder of radius r1 w/ a cylindrical hole of radius r2. Ring’s height=h Find surface area+vol. r1=12m r2=6m h=8m. Write form. w/ r1,r2,h that’ll find SA+V for any ring where 0<r2<r1**

**Answer:**

I believe this is stating that there is an outside cylinder with an

inner core that has been removed. To find the SA of this

outside cylinder, you not only find the SA of that cylinder, but add

the inner core’s SA, which can be found by finding the lateral

SA of the inner cylinder. Then subtract the SA of both top and

bottom circles of that inner cylinder.

You add the lateral surface of inner core’s cylinder SA

because it is the ‘inside’ core of the larger cylinder