A water tank has a rectangular base 1.5m by 1.2m. The sides are vertical and water is being added to the tank at a constant rate of 0.45m^3. At what rate is the depth of water in the tank increasing?

So far, I can say that dV/dt = 0.45, i.e. the rate of change in volume with respect to time is 0.45m^3 / minute.

I do know that the volume would be 1.5 x 1.2 x height.

But I cannot put things together..! (Headbang)

p.s. I have to use the chain rule.