The terms "regular" and "irregular" are used for polygons, not for just any shape.
A semi-circle is actually a specific type of shape known as a "regular" shape. A regular shape is one that has all sides and angles equal. In the case of a semi-circle, it has a curved side and a straight side, but the curved side is a perfectly round half-circle, making it a regular shape. Irregular shapes, on the other hand, do not have sides or angles that are equal.
regular shape is a shape that has same sides irregular shape is a shape that has diffrent sides
irregular
A circle is non-polygon. Meaning it has a curved side. A circle has no sides. It is non-regular.
if it has all congruent sides, then it is regular