The volume of a solid is given by the multiplication of its three dimensions:
In this case we have two similar solids with volumes and , and we only have information about the height of each solid and .
Now, there is a theorem for similar solids, which establishes the ratio of their volume is and the ratio of one of their corresponding sides (the height in this case) is .
Knowing this, we can write the following relation:
Substituting the known values:
Fially finding :