The perfect participle is formed by using the present participle of the appropriate helping verb ( avoir = ayant, être = étant) and then adding the past participle. The perfect participle shows that one action was completed before another action took place:
Ayant fini mon travail, je me suis détendue.
- Having finished my work, I relaxed.
Étant parti de bonne heure, il est arrivé à l'heure.
- Having left early, he arrived on time.