A line has 180 degrees rotational symmetry.
None. For a 3-dimensional object, a line of symmetry implies rotational symmetry and an aircraft has no line of rotational symmetry.
Many figures. For example, an ellipse.
it has two folds.
4
A parallelogram has a rotational symmetry of 2!
triangles have 0 rotational symmetry
it has 5 rotational symmetry
Rotational symmetry of order 1.
It has 1 order of rotational symmetry.
if all of the side are equal to each other, then it will have rotational symmetry. this means that if you stick a line through it and goes through the center, then it is a line of symmetry. the answer is infinity.
A general parallelogram has rotational symmetry of order two.