The height of an equilateral triangular prism increases by three units. The new volume is more than the original by how much?
three times the length of the height
three times the area of the base
three more than the area of the base
three more than the length of the height

Question

The height of an equilateral triangular prism increases by three units. The new volume is more than the original by how much?
three times the length of the height
three times the area of the base
three more than the area of the base
three more than the length of the height

anonymous · Answer

i know for sure it's not c

pfenn1 · Answer

The volume of a equilateral triangular prism is given by  $$V=\frac1 3 Bh$$where B is the area of the base and h is the height.
If the new height is h+3, what happens to the volume, assuming the base area stays the same?

anonymous · Answer

it increases?

pfenn1 · Answer

But in what way?  Do you know how to find out?

anonymous · Answer

3 more then the length of the height?

pfenn1 · Answer

Plug the new height into the formula so you don't have to guess.$$V=\frac13B(h+3)=\frac 13Bh+B$$

anonymous · Answer

if i'm not mistaken, it seems like it would be 3 times the area of the base