Diagonal:
A line segment joining two non-adjacent vertices of a polygon.
Ex: A square has two diagonals.
Here in square ABCD, AC and BD are its diagonals.
Similarly, a hexagon has 3 diagonals.

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A line segment joining two non-adjacent vertices of a polygon.
Ex: A square has two diagonals.
Here in square ABCD, AC and BD are its diagonals.
Similarly, a hexagon has 3 diagonals.