I am assuming that you are asking about the exterior angles of convex polygons.
(1) If you know the interior angles, then the exterior angles are supplementary to the corresponding interior angles.
(2) The sum of the exterior angles of a convex polygon taken one at each vertex is always 360 degrees.
(3) In a regular polygon, all exterior angles are congruent, so to find the measure of one exterior angle simply divide 360 by the number of sides. (e.g. the exterior angles of a regular pentagon are each 360/5=72 degrees.)
(4) In a triangle, of any sort, the measure of an exterior angle is equal to the sum of the two remote interior angles.
Hope that helps.
Assuming that we have convex polygon.
(1)The exterior angle formed by extending one side of polygone is supplementary to the corresponding interior angle.
(2) The sum of the exterior angles of a convex polygon
= n(180- interor angle)=360
n= no. of side of the polygone.
(4) In a triangle, the measure of an exterior angle is equal to the sum of the opposite interior angles.
In regular polygone.
int. angle= ((n-2)x180)/n