Question

Find the volume of the shaded solid. Round your answer to 2 decimal places if necessary. Use π = 3.14 when necessary.

So far I have:

pi(r)^2(h)=v
(3.14)(6^2)(30)=v
3.14(36)(30)=v
113.04(30)=v
3,391.2=v

something just feels wrong, I will post picture following this question

Answer 1

so it's a cylinder with the a smaller middle cylinder missing, ya?

i'd find the volume of the big cylinder, pretending there is nothing missing in the center.
then i'd find the volume of the middle cylinder.
then subtract the two volumes
make sense? ya no?

Answer 2

the inner radius is 3 not 6

Answer 3

i did 18-6=12 12/2 =6 to get the r

Answer 4

the problem with using that r is that there is a hole in the center

Answer 5

im going to try the whole find vol for whole cylinder minus this inner one, thanks for the idea :)

Answer 6

yep ^_^

Answer 7

worked flawlessly!!!

for future students looking for why this works here is the answer:

pi(r^2)(h)=v

3.14(9^2)(30)=v of big cylinder
3.14(81)(30)
7,630.2

3.14(3^2)(30)=v of inner cylinder
3.14(9)(30)
847.8

7,630.2 - 847.8=6,782.4

check mate! thank you again DemolisionWolf

Answer 8

hey, it worked :)
and yes, my *hint* had bad numbers in it, haha.
but ya, you did good ^_^