The minimum order of rotational symmetry a shape can have is 1. Some trapeziums have one line of symmetry. They are called isosceles trapeziums as they have 2 sides of an equal length like ...

The minimum order of rotational symmetry a shape can have is 1. A trapezium has rotational symmetry of order one. Some trapeziums have one line of symmetry. They are called isosceles trapeziums as ...