
A hexagon has nine diagonals. The formula for the number of diagonals is n(n-3)/2, where n represents a side. If there are six sides, by using the formula, we determine that there are nine diagonals: 6(6-3)/2 = 9.
Fr. Pierre Jacobs, S.J., taught me geometry in 10th grade.
Observed bee geometry arises only if cells are previously arranged in a way that
each one is surrounded by six other similar cells.

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