5
18
It has 8 rotational symmetry.
A
A pentagon has roatotional symmetry only if it is a regulat pentagaon. In that case, it has a rotational symmetry of 360/5 degrees and its multiples. That is, 72, 144, 216, and 288 degrees.
108
18
A regular hexagon has 6 rotational symmetries (rotational symmetry of order six) and 6 reflective symmetries (six lines of symmetry).
It has 8 rotational symmetry.
Infinitely many.
An ellipse has rotational symmetry of order 2.
2
9 reflection
Two.
A regular decagon, which has 10 equal sides and angles, has 10 rotational symmetries. These symmetries correspond to the decagon being rotated by multiples of (36^\circ) (360° divided by 10), including the identity rotation (0°). Therefore, the decagon can be rotated to match its original position in 10 different orientations.
A seven-pointed star has seven rotational symmetries. This means it can be rotated in increments of ( \frac{360^\circ}{7} ) and still appear unchanged. Each of these rotations corresponds to one of the seven points of the star. Therefore, the total number of rotational symmetries is equal to the number of points.
yes
5