The cross-section of a water channel is a trapezium in shape. If the channel is 12 meters wide at the top and 8 meters wide at the bottom and the area of cross-section is 700 square meters, what is the depth of the channel (in meters)?	Choose the correct choice from the following choices
A) 50	B) 60	C) 70	D) 80	E) 90
1/2 * d * (12 + 8) = 700   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 12 meters wide at the top and 8 meters wide at the bottom and the area of cross-section is 700 square meters, what is the depth of the channel (in meters)?