A water trough is 6 m long and its cross-section is an isosceles trapezoid which is 140 cm wide at the bottom and 280 cm wide at the top, and the...

A water trough is 6 m long and its cross-section is an isosceles trapezoid which is 140 cm wide at the bottom and 280 cm wide at the top, and the height is 70 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.