Two similar pipes are shown.

The small pipe has a radius of 18 feet and a height of 21 feet while the large pipe has a height of 28 feet. What is the volume of the large pipe in terms of π?

5,376π ft3

18,432π ft3

6,804π ft3

16,128π ft3

Question

Two similar pipes are shown.
 

 
The small pipe has a radius of 18 feet and a height of 21 feet while the large pipe has a height of 28 feet. What is the volume of the large pipe in terms of π? 

 5,376π ft3 

 18,432π ft3 

 6,804π ft3 

 16,128π ft3

anonymous · Answer

Hint:  If the two pipes are similar, then the rations of their radius to height should be the same.

richyw · Answer

Small pipe: r=18, h=21
Large pipe: H=28

The pipes are similar so$$r/h=R/H$$$$R=Hr/h=28*18/21=24$$
Now just calculate the volume. $$V=H\pi R^2=28(24^2)\pi$$

I don't have a calculator to make sure but I think the answer is D. You will want to use a calculator to make sure.