A concrete dam of height 128 ft. was built in a gorge.One side AB of the gorge slopes at an angle of 60 degrees,and the other side CD at 45 degrees.The bases of the dam are horizontal rectangular in shape .The lower base is 1215 ft. by 152 ft. and the upper base is 32 ft. wide .How many cubic yards of concrete were required?
Answer in cubic yards.
Image [Note: The other angle in the image is 60 not 70]
~Answer: 561230 cubic yards.
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