The number of diagonals in a convex n-sided polygon is given by the formula n(n-3)/2, derived from the total number of line segments connecting all vertex pairs (nC2) minus the n sides of the polygon itself.
For a 12-gon (dodecagon), number of diagonals = n(n-3)/2 = 12(12-3)/2 = 12 x 9/2 = 108/2 = 54. Option 2 is correct.
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