Problem: the cross - section of a cannel is a trapezium in shape . if the cannel is 14 m wide at the top and 8 m wide at the bottom and the area of cross - section is 550 sq m , the depth of cannel is ?
Rationale: "1 / 2 * d ( 14 + 8 ) = 550 d = 50 answer : c"
annotated_formula: divide(divide(divide(550, divide(add(14, 8), const_2)), 8), const_2)