Here mine dog "Flame" has actually her face made perfect symmetrical v a bitof photograph magic.

The white line down the center is present of Symmetry


When the folded part sits perfect on top (all edges matching), climate the wrinkles line is a heat of Symmetry.


Here I have folded a rectangle one way, and it didn"t work.

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So this is not a line of Symmetry

But as soon as I shot it this way, that does work (the folded part sits perfectly on top, all edges matching):

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So this is a line of Symmetry

Triangles

A Triangle have the right to have 3, or 1 or no currently of symmetry:

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Equilateral Triangle(all sides equal, all angle equal) Isosceles Triangle(two political parties equal, 2 angles equal) Scalene Triangle(no sides equal, no angle equal)
3 currently of Symmetry1 heat of SymmetryNo lines of Symmetry

Quadrilaterals

Different species of quadrilaterals (a 4-sided aircraft shape):

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Square(all sides equal, all angles 90°) Rectangle(opposite sides equal, all angle 90°)Irregular Quadrilateral
4 present of Symmetry2 currently of SymmetryNo present of Symmetry

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KiteRhombus(all sides same length)
1 line of Symmetry2 present of Symmetry

Regular Polygons

A continual polygon has actually all sides equal, and all angle equal:

An Equilateral Triangle (3 sides) has 3 currently of Symmetry
A Square (4 sides) has 4 present of Symmetry
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A Regular Pentagon (5 sides) has 5 present of Symmetry
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A Regular Hexagon (6 sides) has 6 currently of Symmetry
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A Regular Heptagon (7 sides) has 7 currently of Symmetry
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A Regular Octagon (8 sides) has 8 present of Symmetry

And the pattern continues:

A continual polygon that 9 sides has actually 9 lines of SymmetryA regular polygon of 10 sides has 10 currently of Symmetry...A regular polygon the "n" sides has actually "n" currently of Symmetry

Circle