What is the length of one side of a triangle when its opposite angle measures 60 degrees, one adjacent side is 8 units, and the other adjacent side is 10 units?
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Question: How many diagonals does a regular heptagon have?
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What is the average (mean) number of books read per month by a group of 20 students given the following data: 12, 14, 9, 10, 15, 11, 8, 13, 17, 16, 7, 12, 9, 11, 15, 13, 9, 12, 14, 10?