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.
Yes.
Lines of symmetry in polygons are not necessarily diagonals. A line of symmetry divides a shape into two identical halves, while a diagonal connects non-adjacent vertices of a polygon. In some cases, a diagonal can serve as a line of symmetry, but this is not true for all polygons. Therefore, while there can be overlap, the two concepts are distinct and not synonymous.
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.
no
A circle (infinitely many lines of symmetry), ellipse, rectangle, and all regular polygons.
All regular ones do.
Yes.
All of them have rotational symmetry because all the sides and angles have to be the same in order for the polygon to be a regular polygon
This is false. The statement would be true for regular polygons, but not all polygons are regular.
All regular polygons A polygon is symmetrical if its sides that cross the line of symmetry are halved by the line of symmetry and if the sides that do not cross the line of symmetry have the same positions in space, the same lengths, and the same angles with their neighboring sides as do the sides on the other side of the line of symmetry. The only symmetrical triangles are isosceles triangles (equilateral triangles are isosceles). The only symmetrical quadrilaterals are squares, rectangles, rhombi (the line of symmetry connects either pair of opposite corners), isosceles trapezoids, and kites.
An equilateral triangle, and all regular polygons with 3n sides.
All regular shapes have a line of symmetry. But you can get rid of its line of symmetry by making it irregular (so the angles aren't the same).