A rectangular glass fish tank, the bottom is a square with a circumference of 80 cm, now pour 6 liters of water into the tank, how many cm is the water depth in the tank?

A rectangular glass fish tank, the bottom is a square with a circumference of 80 cm, now pour 6 liters of water into the tank, how many cm is the water depth in the tank?

Bottom length = 80 △ 4 = 20cm
6 L = 6000 CC
Water depth = 6000 △ 20 △ 20 = 15 cm