A regular shape, also known as a regular polygon, is a shape that has sides that are all equal. If there are sides of differing lengths, these shapes are known as irregular polygons.
As well as having all sides equal in length, all interior angles must also be the same. For example, a triangle with three sides of equal length and all three internal angles of 60 degrees, which is also known as an equilateral triangle. However, not all regular shapes are equilateral because while an equilateral polygon can have all sides exactly the same length, they must also have the same internal angles.