A regular pentagon has 5 congruent sides
An... irregular pentagon?
i don't know; that person is wrong it is a regular pentagon that has all sides congruent
A polygon with five congruent sides is a pentagon.
Not necessarily; if it is a regular pentagon, then yes.
a regular pentagon or just a pentagon
A regular pentagon does not have any parallel sides. In contrast, a pentagonal prism has two parallel and congruent bases.