yes
All regular polygons do.
almost all even number of sided polygons, regular has to be
There would be too many to name. All regular polygons have a line of symmetry, but there are still polygons that don't.
Regular polygons.
A circle (infinitely many lines of symmetry), ellipse, rectangle, and all regular polygons.
no
yes
yes
All regular ones do.
Yes.
A regular polygon has a number of lines of symmetry equal to the number of its sides. For example, a regular pentagon has 5 lines of symmetry, while a regular hexagon has 6. Each line of symmetry divides the polygon into two congruent halves, reflecting the shape across the line.