The cross-section of a cannel is a trapezium in shape. If the cannel is 10 m wide at the top and 6 m wide at the bottom and the area of cross-section is 640 sq m, the depth of cannel is?  Pick one:  A) 39  B) 28  C) 27  D) 80  E) 71
1/2 * d (10 + 6) = 640   d = 80   Answer: 80
<result>D</result>
The cross-section of a cannel is a trapezium in shape. If the cannel is 10 m wide at the top and 6 m wide at the bottom and the area of cross-section is 640 sq m, the depth of cannel is?