There is a log of precious wood 18 feet long whose bases are 5 feet and 2.5 feet in circumference. Into what lengths should the log be cut to trisect its volume?

*Jinkō-ki* (*Treatise on Large and Small Numbers*), Yoshida Kōyū, 1627

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The answer is: with the widest end on the left, the left length would be approximately 3.909 feet, the middle length would be approximately 5.202 feet, and the right length would be approximately 8.889 feet.