An ellipse has rotational symmetry of order 2.
None, however the semicircle has one folding axis of symmetry perpendicular to the midpoint of the straight side
6
For a star shaped figure, as many as the number of points. For a real star (like the ones up in the sky) either infinitely many or none - depending on the level of detail that you look at. The surface of any star has lots of dimples and bumps caused by stellar activity and these will break up any symmetry. If you ignore these fine details, then the star is a smooth ellipsoid and has infinitely many rotational symmetries. These symmetries are along the star's axis of rotation. For any other axis, the star's rotation will make the equatorial region bulge out and so there will be no symmetries.
I think 5
It has 8 rotational symmetry.
Infinitely many.
An ellipse has rotational symmetry of order 2.
2
9 reflection
18
5
Two.
A regular hexagon has 6 rotational symmetries (rotational symmetry of order six) and 6 reflective symmetries (six lines of symmetry).
A kite has only one line of rotational symmetry, as it is only the same if it is tilted once. (back to its normal position).
None, however the semicircle has one folding axis of symmetry perpendicular to the midpoint of the straight side
6