Answer:
40
Step-by-step explanation:
Any regular polygon has exterior angles = to 360 / number of sides.
so a 9-gon has 9 sides. The exterior angle = 360 / 9 = 40
Each exterior angle will be 40 degrees.
Try it with simpler n-gons. A triangle has 3 sides. The exterior angle is 360 / 3 = 120
A square has 4 sides. Each exterior angle is 360 / 4 = 90