Liu Hui (fl. 3rd century) was a mathematician of the state of Cao Wei during the Three Kingdoms period of Chinese history. In 263, he edited and published a book with solutions to mathematical problems presented in the famous Chinese book of mathematics known as The Nine Chapters on the Mathematical Art (九章算术).
He was a descendant of the Marquis of Zixiang of the Han dynasty, corresponding to current Zixiang township of Shandong province. He completed his commentary to the Nine Chapters in the year 263.
He probably visited Luoyang, and measured the sun's shadow.
Read more about Liu Hui: Mathematical Work