the cross - section of a cannel is a trapezium in shape . if the cannel is 8 m wide at the top and 6 m wide at the bottom and the area of cross - section is 700 sq m , the depth of cannel is ?
"1 / 2 * d ( 8 + 6 ) = 700 d = 100 answer : b"
divide(divide(divide(700, divide(add(8, 6), const_2)), 6), const_2)