The volume is V=LxWxH. Â The length x Width is just the area, A, of the bottom (also of the top) Â So you could also write V=AxH, that is volume is
area x height. Â Since we know V equals 972 and A equals 81Â we can solve for H:
V=AxH
972=81H
972/81=H
H=12cm