Answer:
40
Explanation:
The angle marked x is an exterior angle of the polygon.
The sum of the measures of the exterior angles of a polygon, one exterior angle per vertex, is 360 deg.
In a regular polygon, all exterior angles are congruent. The number of exterior angles, one per vertex, is the same as the number of sides.
We count the number of sides of this polygon and see it has 9 sides.
Since it is a regular polygon, he measure of each exterior angle is 360 divided by the number of sides.
x = 360 deg/9 = 40 deg