Question 1049769
A hexagon has 6 sides.
tan(180/6) = tan(30)
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The apothem is the distance from the center to the center of any side.
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It is a formula using the apothem.
If you like I can do it without the formula.
I thought you wanted the answer --- "It's not a homework problem."
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Your answer was off by a factor of 2.  You used the distance across the flats in your calculations when you should have used the distance from the center to the flats.