Any regular polygon has 3 (or more) lines of symmetry.
A square is on example. The perpendicular bisectors of the sides and the two diagonals comprie four lines of symmetry.
A symmetrical shape is a mirror image of a shape when a line is drawn through it and some shapes have many lines of symmetry or none at all.
A Heart or a Triangle.
It is an imaginary line that produces a mirror image of a shape which is its line of symmetry
All triangles have less than 4 lines of symmetry.
Any regular polygon has 3 (or more) lines of symmetry.
A square is on example. The perpendicular bisectors of the sides and the two diagonals comprie four lines of symmetry.
A symmetrical shape is a mirror image of a shape when a line is drawn through it and some shapes have many lines of symmetry or none at all.
A Heart or a Triangle.
A circle has an infinite number of lines of symmetry, corresponding to any of its diameter lines, to any arbitrary level of division (degrees, minutes, seconds).
It is an imaginary line that produces a mirror image of a shape which is its line of symmetry
Lines of symmetry, I think is what you meant to write, is... well it's easier this way: Think of any shape: in this example we'll use a square. ONE of its lines of symmetry is right down the middle, because then both sides are the same. So, a line of symmetry is a line that divides a shape into to exactly the same shapes (except they are facing the other way.)
Any shape that contains a section of a plane can have an infinite number of parallel lines in it.
circle
There is no such shape since an angle can always be added to any shape.
There is no such shape since it is always possible to add another side.