hydrostatic pressure and force

Question

An aquarium  m long,  m wide, and  m deep is full of water. Find the following:the hydrostatic pressure on the bottom of the aquarium     ,the hydrostatic force on the bottom of the aquarium     ,the hydrostatic force on one end of the aquarium 

Answer 1

The pressure at the bottom of the tank = rho*g*depth= 997*9.81*3= 29342 Pascals.

The force on the bottom of the tank = Pressure * Area = 29342* 7*4= 821567 Newtons

The force on one end = Pressure at centroid of End * Area of end = rho*g*depth/2*(4*3)= 17481 Newtons