The regular polygon whose exterior angle is 40∘ is a:
Nonagon
Sum of external angles of any polygon is 360∘
Since it is a regular polygon, all the exterior angles are equal i.e., 40∘ each.
Exterior angle = 360°n; where n is the number of sides.
⇒ n =360°40°
⇒ n = 9
It is a nonagon.