Question

The height of an equilateral triangular prism increases by 3 units. The new volume is more than the original by how much?

Answer 1

what was the original?

Answer 2

Think, what is the formula for the volume of a triangular prism? and the original numbers don't matter

Answer 3

But if you need to know the difference between the original and the current don't you need to know the original?????

Answer 4

Not necessarily. the volume of a prism is area(base) times length. The new length is the same, and the height changes, which means the bases change. Let's say the original side length was x and the length was L. Original volume was x(sqrt(3)x/2)(L). The new base is (x/2)+(3x/sqrt(3), making the new volume ((x/2)+(3x/sqrt(3))(sqrt(3)/2 +3)(L). Subtract the old volume from the new volume, and you have the answer. This problem is a bit messy, but it can be done with variables instead of numbers if they are not provided.