Definition
Regular polygon
A regular polygon has equal side lengths and equal interior angles.
What it means
Both tests matter. Matching side lengths alone are not enough, and matching angles alone are not enough. Turning or resizing the polygon does not change whether it is regular.
Remember it
Same sides, same inside angles, all the way around.
Example
A hexagon has six sides of 4 cm and six interior angles of 120°. All six sides match and all six angles match, so it is a regular hexagon.
Watch for
A non-square rhombus has four equal sides but two different angle sizes, so it is not a regular polygon.
Common mix-up
“Regular” does not mean common-looking; it describes exact equalities.
Exact meaning
A regular polygon is a closed, flat figure with straight sides in which every side has the same length and every interior angle has the same measure.