Question: the cross - section of a water channel is a trapezium in shape . if the channel is 12 meters wide at the top and 6 meters wide at the bottom and the area of cross - section is 630 square meters , what is the depth of the channel ( in meters ) ?
A) 50
B) 60
C) 70
D) 80
E) 90
Correct answer: C
Grade: 7 | Topic: Geometry | Difficulty: Hard | Standard: 7.G.B.6