The cross-section of a cannel is a trapezium in shape. If the cannel is 6 m wide at the top and 4 m wide at the bottom and the area of cross-section is 10290 sq m, the depth of cannel is?
Pick:
A) 258
B) 260
C) 262
D) 264
E) 266

Rationale: 1 / 2 * d ( 6 + 4 ) = 10290 d = 258 answer : a
Answer: A