Answer: 14.32 degrees
The circle has a diameter of 8 kilometers, so the perimeter would be:
perimeter= pi * diameter
perimeter= 22/7 * 8 kilometers= 25.14 kilometers
A full perimeter of the circle, which is 25.14km, has 360° angle. So 1km arc would be: 1km/ 25.14 km * 360°= 14.32°