The cross-section of a cannel is a trapezium in shape. If the cannel is 15 m wide at the top and 9 m wide at the bottom and the area of cross-section is 636 sq m, the depth of cannel is?	Choose the correct choice from the following choices:
A) 53 B) 28 C) 27 D) 80 E) 25
1/2 * d (15 + 9) = 636   d = 53   53nswer: 53
<result>A</result>
The cross-section of a cannel is a trapezium in shape. If the cannel is 15 m wide at the top and 9 m wide at the bottom and the area of cross-section is 636 sq m, the depth of cannel is?