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 770 square meters, what is the depth of the channel (in meters)?  Pick one.
A) 50 B) 60 C) 70 D) 80 E) 90
1/2 * d * (14 + 8) = 770   d = 70   The answer is 70.
<result>C</result>
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 770 square meters, what is the depth of the channel (in meters)?