yes
The rectangle's rotational symmetry is of order 2. A square's rotational symmetry is of order 4; the triangle has a symmetry of order 3. Rotational symmetry is the number of times a figure can be rotated and still look the same as the original figure.
a circle or a sphere
A circle and square.
Line
A figure has rotational symmetry if you can turn it about a figure.
A sphere has rotational symmetry of an infinite degree.
yes
yes
The rectangle's rotational symmetry is of order 2. A square's rotational symmetry is of order 4; the triangle has a symmetry of order 3. Rotational symmetry is the number of times a figure can be rotated and still look the same as the original figure.
Yes. An ellipse (oval) has two lines of symmetry, but not a rotational symmetry. A parabola has one line and no rotation.
a circle or a sphere
z
a right triangle
A circle and square.
Yes. A circle has infinitely many lines of symmetry and it also has rotational symmetry of infinite order.
A figure has rotational symmetry if it can be rotated by a certain angle (less than 360 degrees) and still looks the same. The number of times you can rotate the figure and have it look the same determines the order of rotational symmetry - a square has rotational symmetry of order 4, for example.