A water trough is 8 m long and its cross-section is an isosceles trapezoid which is 120 cm wide at the bottom?

A water trough is 8 m long and its cross-section is an isosceles trapezoid which is 120 cm wide at the bottom and 180 cm wide at the top, and the height is 60 cm. The trough is not full. Give an expression for V, the volume of water in the trough in cm3, when the depth of the water is d cm.