the cross - section of a water channel is a trapezium in shape . if the channel is 14 meters wide at the top and 8 meters wide at the bottom and the area of cross - section is 880 square meters , what is the depth of the channel ( in meters ) ?
"1 / 2 * d * ( 14 + 8 ) = 880 d = 80 the answer is d ."
divide(880, divide(add(14, 8), const_2))