the cross - section of a cannel is a trapezium in shape . if the cannel is 5 m wide at the top and 3 m wide at the bottom and the area of cross - section is 3800 sq m , the depth of cannel is ?
"1 / 2 * d ( 5 + 3 ) = 3800 d = 950 answer : d"
divide(divide(divide(3800, divide(add(5, 3), const_2)), 3), const_2)