How Many Lines of Symmetry Does a Decagon Have?

By Staff WriterLast Updated Mar 26, 2020 11:31:50 PM ET
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A regular decagon has 10 lines of symmetry, one line drawn through each vertex and one line drawn through the midpoint of each edge. A line of symmetry indicates where a polygon can be folded in half to form two equal shapes.

The number of lines of symmetry in regular polygons is equal to the number of sides of the polygon. A regular decagon is a two-dimensional polygon with 10 sides of equal length, so it has 10 lines of symmetry. Most irregular polygons do not have a line of symmetry, with the isosceles triangle and rectangle serving as two exceptions.