Final answer:
An irregular polygon with rotation symmetry for an angle of 20° has 18 sides and may not have any lines of symmetry.
Step-by-step explanation:
An irregular polygon is a polygon that does not have all sides or angles equal. Rotation symmetry means that the polygon looks the same after rotating it by a certain angle. In this case, the angle of rotation symmetry is 20°.
For a regular polygon, the angle of rotation symmetry is always 360° divided by the number of sides it has. To find the number of sides in the irregular polygon, we can divide 360° by the given angle of rotation symmetry: 360° ÷ 20° = 18.
So, the irregular polygon has 18 sides. As for lines of symmetry, it may not have any lines of symmetry, as irregular polygons can have varying numbers of lines of symmetry. The number of lines of symmetry depends on the shape and arrangement of its sides and angles.
Learn more about Irregular polygons