Visual inspection. It's usually pretty obvious.
"you" is a word, not a letter and it does not have rotational symmetry.
No, a parallelogram does not have rotational symmetry because it cannot be rotated onto itself. Rotational symmetry requires an object to look the same after being rotated by a certain angle.
Yes, it is possible to have a shape that has a line of symmetry but does not have rotational symmetry. An example is the letter "K", which has a vertical line of symmetry but cannot be rotated to match its original orientation.
The letter H has a rotational symmetry of order 2, meaning it looks the same after a 180-degree rotation.
yes, it has a rotational symmetry of 180 degrees, and of course 360. like if you flipped it upside down, then put it on top of the other one it would look the same. just not a lowercase.
A figure has rotational symmetry if you can turn it about a figure.
When you rotate it around a point found in the middle of the figure 180 degrees. For example, H does have rotational symmetry however, E doesn't
yes
A sphere has rotational symmetry of an infinite degree.
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.