The volume (V) of a box:
V = Ab*h
Ab = Area of Base
H = height
If the base of the ring box measures 1 x 1 = 1 cm² and we have 15 rings in the base,
Ab = 15* 1 = 15 cm²
If the height of the ring box is also 1 cm, we can put 9 boxes in each colun. That is, we can have 9*15 ring boxes = 135 ring boxes
The volume of the box:
V = Ab*h
V = 15*9
V=135 cm³